WHEN HENRY Haller talks, everyone listens. That's true whether he's wearing his white toque as executive chef at the White House, or dressed in a sports shirt and slacks as master of his suburban Potomac ranch house.

One recent, sultry summer afternoon Haller was doing the cooking at home, something he does three or four times a month. When the Swiss-born chef is in the kitchen, he gives the orders, in this case to his wife, Carol, and his daughters, Nancy and Susan. He tells 17-year-old Susan, the family's bread baker, to "defrost the bread by spreading it out." He asks his wife how long the rice is cooking. "I don't know," she says. "I just cook it till it's done." In the meantime he is finishing up the carrots and sugar snap peas, warming the plates and the poached chicken in the oven "at 175 degrees."

Haller says "it takes two hours to fix the meal if you are being realistic." He had begun preparations at 4 o'clock, poaching the chicken, slicing the carrots into uniform ovals, starting the sauce supreme which is what makes his poached chicken different from what you are likely to encounter at most family dinners in Potomac. His daughters had sliced the fresh fruit, which would be served with the macaroons that had been prepared the night before.

Haller didn't actually work steadily for two hours. He paused often to kibitz with his wife and children as they came in from work. Before his wife went back to work in February she had done most of the cooking with help from their oldest daughter, "using father's recipes, though sometimes we experiment, too," Nancy explained. Now Susan and Nancy prepare most of the meals.

Susan has been the baker because "it's more of a challenge," especially trying to satisfy her brothers' seemingly insatiable demand for cookies: "They eat them up so fast, I can't keep up."

Haller says both he and his wife "want the girls to know the basics, the boys, too. If they marry girls who don't know how to cook, they're stuck."

But typical of most American, and European households, the sons contribute little to food preparation. They do a fine job consuming what they are served. Richard, now 19, says, "I can do what anyone else can - hamburgers, roasts, spaghetti, eggs. I suppose I can do more than the average American because I've watched my father cook. I definitely want to learn to cook better."

His father interrupts, questioning Richard's talents in the kitchen. "Now wait a minute. Who knows how to flip an egg? It's not so easy."

Robert, on the other hand, the oldest, says he hasn't had much chance to learn. The senior Haller has an explanation: "He's afraid to ask his father...because I'm a perfectionist."

Those who know the 56-year-old Haller will not argue with this judgment. Whether he is arranging platters of salmon mousse for a state dinner at the White House, where he has been executive chef for four presidents, or spooning the supreme sauce over the chicken he has poached for a family dinner, everything must be just so.

The Swiss are known for their precision, and Haller studied and apprenticed in his native country. After that he followed the nomadic career of many European chefs who migrated to this country after World War II. He made his way first to Canada in 1948, then, three years later, to Phoenix. The White House plucked him from the Sheraton East in New York City in 1966. He and Carol met in 1953 when she worked as a waitress at a Martha's Vineyard hotel where Haller was the chef.

Haller taught his wife almost everything she knows about cooking. "The only thing I could make was apple pie," says Carol Haller. "But my husband didn't like it. He liked the Swiss kind."

Mrs. Haller says she never cared much about cooking until recently, when she got interested in vegetables. Her garden is flourishing and includes the newest taste sensation, sugar snap peas. Herbs grow as lushly as a crop of weeds after a rainstorm. The Hallers have had a garden since they moved to Potomac 13 years ago. Mrs. Haller says her husband helps her with the garden. "In the spring Henry goes out and turns the garden over. Then he says, "Your garden is ready." The rest is up to Mrs. Haller.

There is little that distinguishes the Hallers' house, a model home purchased complete with the furniture, from others in suburbia. The kitchen table is covered with a flowered plastic tablecloth. The sewing machine is in the dining room because all the women in the family sew. It's only when you are in the living room that you know the man of the house has an unusual job. There are signed photographs from the Carters and Fords, a letter from Richard Nixon.

When the Ladies Home Journal came to do a story about the Hallers several years ago they changed everything around - "the clothes, the drapes, the china" - much to the Hallers' surprise, and amusement.

But there is a lot that distinguishes what the Hallers eat. Henry Haller's profession has made a difference.Not only because the children have been exposed to the more sophisticated cuisines of Europe, but because they have not been permitted to eat TV dinners, junk food, (except for an occasional potato chip or cookie), or much of anything that is store bought. They have always been encouraged to try new foods. When something different was served for dinner, it was a case of eat it or nothing. As a result they have few prejudices, although one doesn't like liver, another dislikes eggplant.

As with many American families, dinner is served in the kitchen. But there is no pot-to-plate service. Everything is put on platters. Sometimes there is wine, though the children prefer milk.

The food is not really complex, but made of the best and freshest ingredients, expertly prepared. The kind from which there are never leftovers.

The icing on the cake for Carol Haller is that her husband always washes his own pots and pans.

POACHED CHICKEN WITH SUPREME SAUCE

(6 servings)

2 (3-pound) chickens, cut up

1 clove garlic, crushed

3 medium onions, cut up

3 medium carrots, peeled and sliced coarsely

1 sprig parsley

2 stalks celery

Bouquet garni of pinch thyme, marjoram rosemary and oregano, 24 peppercorns, lemon rind

2 cups dry white wine

1 quart water

1 tablespoon salt

Juice of 1/2 lemon

Remove the legs and back from the chickens. Flatten the breasts to speed cooking. (Save the wings and back for stock). Place the vegetables and seasonings on the bottom of a heavy pot. Add the breasts and four legs. Add the wine, water, salt and lemon juice. Place a plate on top of the chicken so that it stays under the liquid. Cover the pot and bring to a boil. Reduce heat and simmer 40 minutes.Let stand for 10 minutes; remove chicken, strain bouillon through heavy cheesecloth. (You should have 5 or 6 cups of liquid.)

SAUCE SUPREME

6 tablespoons butter

6 tablespoons flour

4 1/2 cups chicken bouillon

1 teaspoon Worcestershire sauce

3/4 cup light cream (about)

Melt the butter. Stir in the flour. Off the heat, stir in the bouillon and whisk. Add the Worcestershire sauce. Cook quickly so sauce reduces and gets shiny. Keep stirring. Add the cream, two tablespoons at a time, to thin the sauce.

Remove the skin from the chicken. Arrange on a heated platter and spoon over the sauce.

CARROTS AND SUGAR SNAP PEAS

(6 servings)

1/2 tablespoon butter

1 1/4 pounds carrots, scraped and sliced into ovals

1/2 teaspoon salt

1 teaspoon sugar

Pinch white pepper

Sugar snap peas*

Heat the butter in a saute pan. When it sizzles add the carrots, salt, sugar and pepper and just enough water to cover. Boil quickly until the water evaporates and the carrots are done. Then cover.

Cook the peas in salt water for 3 minutes. Drain, add to carrots and serve immediately. (FOOTNOTE)

* Not only is it difficult to find sugar snap peas, but when you do they are very expensive in the markets. So the amount you add will depend on your pocketbook. Snow peas can be substituted. (END FOOT)

RICE PILAF

(6 servings)

4 cups water

1 bay leaf

1 tablespoon butter

1 1/4 teaspoons salt

2 cups converted rice

Bring water to boil. Add remaining ingredients and bring to boil. Stir; cover and boil quickly until water evaporates, about 25 minutes. Let stand 5 to 10 minutes, covered, and then serve.

COCONUT MACAROONS

(Makes about 4 dozen)

4 egg whites

Pinch salt

1 cup sugar

1 teaspoon vanilla

2 cups shredded coconut

Beat whites with salt until stiff. Gradually beat in sugar until stiff shiny peaks form. Fold in vanilla and coconut. Drop by teaspoon on baking sheet which has been greased and floured or covered with wax paper. Bake on middle shelf of oven at 325 degrees for 20 minutes. CAPTION: Picture 1, no caption; Picture 2, Henry Haller, executive White House chef to four presidents, brings the same sophistication and creativity to family dinners as he does to state dinners. Photos by Harry Naltchayan - The Washington Post