KINSEY PROVED that people were perfectly willing to talk about their sex lives if only you asked. But his book would have been much slimmer if he'd tried to get people to talk about their private chefs.

Afraid to sound extravagant, they prefer to hide behind the convenient myth that the entire American population lives off McDonald's hamburgers. They sit quietly camouflaged in the statistics of economic belt-tightening. And they live in fear of not only being accused of fiddling while Rome burns, but of looking on helplessly while someone raids their kitchen and makes off with their personal Escoffier.

Washingtonians do not want to talk about their private chefs. And they certainly don't want anybody else to talk about them--or to them. They were, however, perfectly willing to talk about other people's private chefs, and even begged that if a reporter managed to gain access, "Do tell us what it costs."

Thirty-six thousand dollars a year if you go for the top.

Most household staffs' salaries range from as little as $18,000 a couple to $20,000 a person (about 15 percent more in New York than Washington), often including room and board, said Glen Scott Greenhouse of the Pavillion Agency in New York, which handles "personal service" accounts throughout the country. "It's a fabulous deal, especially if they're living in," he explained. "They can save all their money." At the Culinary Institute of America (CIA) in Hyde Park, N.Y., placement coordinator Dell Hargis said he gets three or four calls a month for private chefs, and the pay runs from $13,000 to $28,000 a year plus housing, benefits, often a car and its insurance, and bonuses for working parties. The Family Life

Mara Mori Prologo remains a private chef simply because she likes the family life; a home in Northwest Washington is a good place to bring up her daughter. When she was cooking for the Italian ambassador in Moscow, a television reporter tried to tempt her to work for him by promising to pay her with a blank check every month. She wasn't interested. She stayed with her "family" for a dozen years, in Moscow, Austria, France and Washington, leaving only when she got married and moved back to Italy. Now widowed and the mother of a 12-year-old, Prologo cooks for an Italian-German couple with one son at home and another in college nearby, in a household that includes two Spanish-speaking servants--they all manage to communicate somehow.

Obviously she likes children. In fact, she insists on getting up at 6 a.m. to squeeze the orange juice fresh for her employer's son because, "I don't like that he comes in the kitchen in the morning and there's nobody there." And since Saturday is her day off she bakes a cake for him every Friday.

One advantage of a private chef's having children in the house is that there is somebody to cook for. All too often the adults are on diets or eat out, and a chef can find herself occupied with little but salads and plain grilled fish.

When her employer's older son brings friends home from college for an evening of watching television, Prologo serves them onion-parmesan canapes and a "casual" dinner of pasticcio--pigeon and pasta pie, a recipe her mother learned from the chef of an Italian count. The table is set with silver service plates and crystal glasses for the beer and Cokes, and whimsical sculptures are centerpieces on the white tablecloth. The bread has been home baked (of buckwheat if the parents are home and having caviar with it). For dessert, there is floating island drizzled with caramel. Snacks in the household are stiacciata (white pizza) or Prologo's homemade coffee cake. For the two children's return from school at 3:30 she makes an entire meal of meat, vegetables and dessert. Dinner is ordinarily light, just soup and salad, but the family entertains at dinner parties as often as three times a week.

For Prologo there is a right way to do things or no way at all. "We never have a buffet inside this house," she says proudly. The orange juice, whether for breakfast or for screwdrivers, is always freshly squeezed. The toast is homemade, as is the ice cream. At a dinner party, after a pasta course such as green fettucine, ham and mushrooms wrapped in packets of white noodles--all homemade, of course--or one of her hundred risotto variations, Prologo serves along with the meat or fish three or four fresh vegetables ("no peas, no carrots," she insists) plus salad, then a "spoon dessert" such as semifreddo, mousse or a fruit granita. Although she didn't want to at first, she even cooks fresh food for the dog: lots of vegetables, rice and meat, no salt.

In addition to a salary of $300 a week and a home for her and her daughter ("It's like I'm in my own house"), Prologo gets a month vacation in Italy, and spends a month or more with the family in Germany and sometimes at Christmas. In this job Prologo gets to cook to her heart's content, to experiment, but at a comfortable pace. There was no hesitation in turning down "a very good offer in an Italian hotel" three years ago, said Prologo: "In a restaurant they kill you; you have to cook fast." Bachelor Woes

One bachelor-around-town has been through it all with private chefs. He found that the chef could be very accommodating at first, but then might decrease his work or increase his demands, once even while the employer was putting the chef's son through college and medical school. One of his chefs cooked very well if he liked the guests, but "if he didn't like them he'd overcook the food." As a bachelor, he required little routine cooking, but still he said, "If I could get a really good chef . . . it would be a great luxury." Supply and Demand

"There's quite a demand for chefs to work in homes and companies," said Greenhouse. He gets a request a week from Washington for a private chef, or over 10 a week if you include cook-housekeepers. More working women create a need for household services and, "There's a lot of money out there today; there's a lot of new wealth," he claimed. If you go up and down New York's Park Avenue, said Greenhouse, "Every one of those apartments is occupied by a real live millionaire."

It seems on the face of it that there are more chefs than jobs available, suggested Greenhouse, but most of those "chefs" lack credentials. Finding an experienced chef is difficult, which is why employers who have one are so secretive. Young chefs who have not been in private service are most likely to accept jobs cooking on boats--because there is "less a servant attitude" toward them.

In Washington the few employment agencies that remain in existence don't get calls for private chefs. One said it never gets a call for one or an application from one, because in Washington people tend to use caterers or include cooking in a general housekeeper's duties. At L'Academie de Cuisine in Bethesda there is a call for a private chef about once a month, though one month three calls came from the Middleburg area alone. Students who finish L'Academie's cooking course, said Francois Dionot, the school's director, are not yet ready to become chefs, so potential employers are likely to look elsewhere. Elsewhere could be anywhere from the butcher--New York butchers have been known to act as informal agents for chefs--to friends posted overseas who are willing to do some searching. Many employers wind up training housekeepers to be chefs (and occasionally vice versa). When Less Is More

Paul Masih does housekeeping as well as cooking for his part-time job in Georgetown. His first job when he switched from farming to cooking 15 years ago in Pakistan, was for the Iranian embassy there; that took him to Iran and then to the Iranian embassy in Washington in 1975. He's tried working for caterers and restaurants, but since he has problems with his leg, he found standing in a restaurant kitchen painful and a house more comfortable than a hotel or embassy.

"I can cook for 200 people, 300 people, 400 people, 1,000 people," says Masih, but in his present job he never cooks for more than eight, and that's not very often. Actually he doesn't do a lot of cooking at all. His employers--who didn't want their name revealed, lest someone try to steal their chef, they said--eat lightly and are often out. He may prepare two or three meals a week--or none. Sometimes dinner is just broiled fish and salad. "If they have company I love it," says Masih, "because I have a chance to do something different. Culinary Emergency

Several years ago a woman called a friend with a desparate question. Her sister's chef had quit, and in going through the kitchen the sister had found a closet full of truffles. Where could she get truffle recipes? Almost Like a Marriage

In Milwaukee Liane Kuony runs the Postilion School of Culinary Arts in a 19th-century mansion, training about 120 students a year. Ten percent of them become private chefs. "It's a much quieter position" than restaurant cooking, she said. But its greatest advantage is that a young chef can learn on somebody else's money and without the pressure of feeding 60 people at a time. "The worst thing a young person can do is open a restaurant," warned Kuony. It is much better to work in a home, where the money doesn't go first to bringing the kitchen up to code or fixing valves.

As for the problems of being a private chef, they are more emotional than practical. "It's almost like a marriage," said Glen Scott Greenhouse. The high turnover rate is also like modern marriages. The kinds of things that end the relationship are "stupid things" like one of the children bringing home friends from school and expecting the chef-housekeeper to do their laundry.

From the chef's point of view, the job often turns out to be less interesting than it is touted. "People say they want fancy food, but when the chef gets in the job he finds they want pot roast and meatloaf," said Greenhouse. While the chef certainly comes up with his own ideas, he has to respond to the employer's tastes, and often to the employer's particular requests or recipes, which can create problems especially with highly professional chefs. Said Dell Hargis of the CIA, increasingly employers think of chefs as more than servant-cooks, expecting them to polish silver, mop the kitchen, run errands. As Greenhouse explained, 20 years ago people had staffs of a dozen in their houses; now it is only two or four.

On the employer's side, "A lot of people put up with drinking," said Greenhouse, and, "Chefs are temperamental. They throw knives and people out of the kitchen." There is also the concern about security: nowadays employers are requiring polygraph tests as the last step in hiring household help. In Grand Style

One employer willing to show off his chef is Norman Cohn, who gives frequent and legendary parties in his home outside of Philadelphia. Not only are Cohn and his wife Suzanne active in gastronomic societies in Philadelphia and New York, their five children appreciate the culinary arts. Thirteen-year-old Matthew volunteered that his favorite restaurant is La Tour d'Argent in Paris; his older brother Jonathan, when asked which is his favorite local restaurant, wanted to know, "Is New York local?"

Thus they offer rare scope for a chef, even for family dinners.

Their first chef came directly from running one of Philadelphia's most respected restaurants, Les Amis, which she owned for 10 years after leaving the Coventry Forge Inn. After her three years as a private chef with the Cohns, Vicky Rensen said, "Why anybody would stay in the restaurant business I don't know . . . It's too pressured, physically and financially." Most of the responses the Cohns got from their first advertisement were CIA graduates looking to save enough money to open their own restaurant. Thus Rensen was "a big plus" for the Cohns: "Vicky's already done it," said Norman Cohn.

But cooking for the Cohns, even after running a restaurant, wasn't easy. Her restaurant had only 70 seats, and at a restaurant, said Rensen, guests "didn't all come and want appetizers at the same time." The Cohns have matching table service for 300; when they entertain for a mere 40, they have been known to buy new china from Germany for the occasion.

Suzanne Cohn is sympathetic: "To cook for a hundred people in the style we expect is a hard job," she said. For one thing, she doesn't like to serve the same dish twice. She has her own strong ideas on food and its presentation, and Norman Cohn is likely to bring home recipes he has gathered from chefs or food magazines, or even a bunch of chanterelles he would like prepared for dinner. As Rensen described her job interview, "Mr. Cohn said, 'If my wife wants to serve fish with flowers around the neck, what would you say?' I might think she's crazy but I would do it because she's the one who has to face the customers."

The Cohn house is well stocked--six-burner restaurant stove, two warming ovens, three refrigerators, at least two freezers, three dishwashers and a marble-topped island in the pastry room. Rensen had the opportunity to use ingredients she couldn't afford in her restaurant--fresh white truffles to grate on the brie, foie gras, caviar to serve for breakfast. While a chef may feel demeaned by the family cooking--Rensen learned to make tacos, and had to accept the children's predeliction for Lean Cuisine and Cup-A-Soup--there was the chance to make foie gras and sweetbreads in a truffle sauce that involves cooking an ox tongue, sweetbreads, port and a can of truffles in "a demiglace so stiff you can walk on it," then putting it all through a sieve and using only the sauce. "There isn't another family in the U.S. that would even attempt it, it is so expensive," Rensen said.

As chef for the Cohns, Rensen was sent to New York to apprentice with Michel Fitoussi at the Palace restaurant for a week, and invited to take courses at the New York Restaurant School and with Jacques Pepin. Her birthday present one year was dinner for two once a month for a year, in such New York restaurants as the Quilted Giraffe, the Four Seasons and La Tulipe. She had assistance in the kitchen from the Cohn's Finnish governess, who made the breads and pastries, having taken a chocolate course in New York. And the butler-wine steward, Eugene Flynn, studied wine with Kevin Zraly at Windows on the World and at the Waldorf. Their Christmas gift one year was a trip to Africa, and every year the Cohns take their staff to a house--with its own staff--in another part of the world, for a vacation.

Rensen learned to appreciate that as a private chef, "You don't have to meet a quota." She also had a chance to again make casseroles and old fashioned stews. As for cooking children's food, she said, "Matt was 10 with the tastes of a 30-year-old." The only problem she found serious was the lack of privacy; the hours were long, and even on her day off she still was in the same house with her employers. Furthermore, days off depended on the family's needs and were subject to change; Rensen said it was "practically impossible for me to have any steady relationship with anyone."

The pluses? "Money." Not only did she have a car, but it was always filled and inspected and repainted. Her youngest daughter's private school tuition was paid.

It does not leave one wondering why Cohn would be more willing than most to show off his chef. But he has his own reasons: "If we can only keep people by hiding them under a barrel . . . life is too short."

Rensen and the other chefs have also been willing to share their recipes: MARA MORI PROLOGO'S BUCATINI E PICCIONI IN PASTICCIO (6 servings) 3 meaty pigeons (can substitute other poultry) Salt and pepper 1 carrot 2 stalks celery 1 onion 1/2 stick butter, approximately 3 slices prosciutto, chopped 1 1/2 teaspoons flour 1/4 cup marsala 10 ounces bucatini or other thick macaroni 1/2 to 1 cup water mixed with 1 teaspoon bovril or Vegemite (optional) 1/2 cup grated parmesan Beaten egg for wash

Pasta brise'e: 3 cups sifted flour 2 sticks butter Salt 1/2 cup water, approximately

Besciamella: 2 tablespoons butter 1 tablespoon flour Pinch salt 1 cup milk

Choose 3 fat, meaty pigeons. Divide each into 4 pieces. Rinse and dry the pieces, then sprinkle with salt and pepper. (While the traditional method leaves the bones in the birds, boned poultry could also be used.) Chop the carrot, celery and onion finely. Heat 1 tablespoon butter in a large skillet and add carrot, celery, onion and prosciutto. Cook until the vegetables are soft; then add the pieces of pigeon. When the pigeon is brown on all sides, dust with flour and cook a minute or two. Pour in marsala. When the marsala has evaporated, cover the pigeon with water, about 2 cups. Cover and simmer slowly 1/2 hour or until the pigeon is tender and the sauce thick.

To make the pasta brise'e cut flour and butter until coarse crumbs; add a pinch of salt and about 1/2 cup water (enough to form into a ball). Let rest 1/2 hour in the refrigerator.

Break the bucatini into pieces the length of a 9-by-12-inch baking pan. Add the broken bucatini to 4 quarts of boiling salted water, cook until al dente, rinse, place in a bowl.

Remove pigeon pieces from pan. (At this stage you may want to add 1/2 cup or more water mixed with 1 teaspoon bovril if sauce is too thick or needs more richness; boil it down if it is watery.) Add 3 tablespoons butter and the parmesan to sauce. Coat the bucatini with the pigeon sauce.

Butter a 9-by-12-inch baking pan. Divide pasta brise'e into 2 parts, one slightly larger than the other. Roll as for pie crust.

To make the besciamella, melt 2 tablespoons butter in a small saucepan and stir in 1 tablespoon flour. Heat, stirring, without letting it brown for 2 to 3 minutes. Gradually stir in milk and bring to a boil. Let simmer 5 minutes, then let it cool to tepid.

Line baking pan with pasta brise'e. Place 2/3 of the bucatini on the brise'e. Add the dozen pigeon pieces. Cover with remaining 1/3 bucatini. Pour the besciamella evenly over all. Carefully insert the blade of a knife to allow besciamella to seep through mixture.

Finally cover the entire dish with the second piece of brise'e, sealing the edges carefully giving the pasticcio a regular form. Brush top with a beaten egg. Bake at 350 degrees for 30 minutes. Serve warm. VICKY RENSEN'S GRAVAD LAKS TARTAR ON ARTICHOKE BOTTOMS WITH MUSTARD DILL SAUCE (12 servings) 5 tablespoons chopped capers 1 1/2 teaspoons chopped shallots 1/2 cup Mustard Dill Sauce (see recipe below) 12 artichoke bottoms (if canned let them soak 1 to 2 hours in slightly sugared water) 1 1/2 pounds Gravad Laks (see recipe below), skinned and chopped fine as you would a beef tartar Black caviar for garnish (optional)

Mix together capers, shallots and mustard dill sauce. Cover the bottom (not rim) of individual plates with sauce. In the center place artichokes mounded with gravad laks tartar and topped with a spoon of black cavair. If you prefer, finely chopped gravad laks can be mixed with the mustard dill sauce to taste and served as a spread for pumpernickel bread instead of serving on artichoke bottoms. GRAVAD LAKS (12 servings) 2 tablespoons sugar 1 tablespoon coarse salt 2 teaspoons white pepper 3 bunches dill 1 1/2 pounds salmon, in 2 fillets with skin left on

Mix together sugar, salt and white pepper. On a large tray or platter spread out 1 bunch of dill--do not wash unless very sandy. Sprinkle on fillet 1/3 salt-sugar-pepper mix. Lay it skin side down on dill, cover with 1 more bunch dill. Sprinkle second fillet with 1/3 salt mix and lay it skin side up on dill. Cover the skin with rest of dill. Sprinkle with remainder of salt mix. Put under a light press for no less than 48 hours, up to 5 days--turning the whole fish once a day. Remove dill, scrape the fish down (with the meat, not against). You may slice it and eat it on pumpernickel or rye as you would lox, or chop it for Laks Tartar. Serve with Mustard Dill Sauce. MUSTARD DILL SAUCE (Makes about 1/2 cup) 3 tablespoons German mustard 1 tablespoon sugar 1 tablespoon white vinegar 3 tablespoons oil Cut fresh dill to taste

Mix ingredients in order listed and serve with Gravad Laks. VICKY RENSEN'S BRIE AU CROUTE (12 servings) 17 1/4-ounce package frozen puff pastry dough 2-pound rather unripe brie 1 egg, beaten Truffles (optional) Black currant jam for serving Green and purple grapes (with leaves if possible) for garnish

Unfold first piece of dough on floured board. Place brie in center and trim a 1 1/2 inch rim around it. Brush rim with beaten egg. Place truffle slices on top of brie. Unfold second piece of dough and roll it gently on floured board until it makes a circle 6 1/2 inches wider than the brie. Place this dough on top of cheese. Fold down the sides of the dough and make small pleats to tighten the dough around the side of the cheese. The top layer of dough should have a 1 1/2-inch overlap corresponding with the bottom layer. Make sure there is egg wash between these two rums of dough. Seal the edges with the prongs of a fork. Bake for 20 minutes at 350 degrees.

Decorate with grapes and cut into wedges; serve with jam. VICKY RENSEN'S RED BASS SICHUAN STYLE (5 to 6 servings)

While Rensen assumes a good Chinese cook could do this in one big wok, she highly recommends a combination of a deep fryer and a wok, lots of old newspapers and by all means a long-sleeved shirt.

Bowl 1: 1 1/2 pounds bass or other fish fillet, cut in 1/2-by-2 inch strips 3 tablespoons dry sherry 1 tablespoon sherry vinegar 2 eggs 2 tablespoons soy sauce

Bowl 2: 1/2 head cabbage, cut in 1-inch pieces 1 large bermuda onion, cut in 1-inch pieces 1 large green pepper, cut in 1-inch pieces

Bowl 3: 3 tablespoons chopped ginger root 3 tablespoons sherry wine 2 tablespoons sherry vinegar 10 scallions, bias-sliced into 1 1/2-inch pieces 3 cloves garlic 1 teaspoon sugar 3 tablespoons fermented black beans

For cooking: 2/3 cup cornstarch Oil for deep frying Scallions for garnish Rice for serving

For bowl 1, marinate fish strips in dry sherry, sherry vinegar, eggs and soy sauce for 2 to 5 hours.

For bowl 2, combine cut cabbage, bermuda onion and green pepper.

For bowl 3, combine ginger root, sherry wine, sherry vinegar, scallions, garlic, sugar and fermented beans.

When all the above is ready and the oil is heated to 375 degrees you will have about 20 to 30 minutes' work.

Remove fish from bowl 1 and lightly pat dry. Roll in cornstarch to coat strips and shake off excess, then deep-fry a few pieces at a time until golden, about 1 to 2 minutes. Keep in a warming oven or hot plate.

Deep-fry contents of bowl 2 for about 3 minutes or until vegetables are slightly browned, being careful when you add them to the oil, as they contain a lot of water.

In the meantime heat a wok and pour in contents of bowl 3. Bring to a boil and simmer 2 to 3 minutes.

To the boiling liquid add the fish, then the vegetables. Taste for seasoning, adding more pepper and soy sauce if necessary. Sprinkle with scallions and serve over rice. PAUL MASIH'S FRIED SNOW PEAS (3 servings) Juice 1/2 lemon 1 pound peapods Dash salt and pepper 1 egg 1/4 cup milk 1/3 cup flour 1/2 teaspoon baking powder Oil for deep frying

Heat oil for deep frying. Squeeze lemon juice on snow peas. Season with salt and pepper. Combine milk and egg in a shallow bowl. In another bowl combine flour and baking powder. Dip snow peas in egg and milk mixture, then dip in flour mixture. Fry in medium-hot oil until browned.

Drain on paper towels and serve immediately.