THE FRENCH, who know a lot about such things, consider good food crucial to good business--important enough, in fact, that they detailed four top chefs to Versailles last week to cater the summit meetings while the world watched and read and savored.

Unfortunately, catered business lunches in Washington are all too often a matter of sandwiching a meal between meetings, with little thought to the content of that sandwich.

No wonder the food is ignored.

Few things are purchased more blindly than a catered lunch. It is nearly impossible to examine ahead of time, it can't be returned if unsatisfactory, and no grapevine of consumers exists to make the choice more rational. Sampling brands of peanut butter on the grocery shelf and choosing a favorite is easy. Making the rounds and picking a favorite restaurant is more costly but still feasible. But testing and finding a suitable caterer is an investment even beyond the most prosperous corporations. How many lunches for 10 or 50 can one order?

Fortunately, at the American Psychological Association, the answer is plenty. Since business lunches are scheduled several times a week, the association's expenditure for caterers is substantial, and the need for choosing well is essential. This year the association agreed to let me in on the process, encouraging its meeting planners to engage a variety of caterers and inviting me to taste each of the lunches (as well as a few dinners). Over the three months, I sampled 10 caterers, most of them several times. The meals' cost per person (including utensils and delivery but not service, as these were buffets) ranged from about $6 to about $16, most under $10. Toward the end of this period, a letter was sent to several dozen caterers inviting them to bring two dishes to a buffet lunch meant to display caterers' wares to the meeting planners. Ten showed up, seven of those new. Thus 17 caterers were evaluated in some way for this survey.

Here are the evaluations of the three months of lunches and dinners, followed by a report on the samples brought to the tasting lunch. THE AMERICAN AMBER GRAIN, FRUITED PLAIN AND SHINING SEA CO. 1414 Q St. NW Washington, D.C. 667-0843

This new caterer in town is developing a patriotic following. It's so good, in fact, that its flaws are suffered gladly. The meeting planners found the company easy to work with and delighted in the imaginative presentation of the food, thus were willing to put up with having to have a check ready when the food was brought.

As for the food itself, Amber Grain can turn a sandwich into a party, a cookie into a celebration. Lunches at $7.70 and $8.66 a person had highly original sandwiches--pita bread filled with large chunks of chicken and broccoli florets, well dressed, peppered and herbed; or mustardy ham and cheese, again with the crunch of broccoli. While the bread needed improvement, the fillings were imaginative and delicious--though some lunchers objected to broccoli hiding in their sandwiches. The two side dishes one day were well-oiled, tangy and peppery sesame noodles tossed with aromatic roast pork and crisp vegetables, and an excellent slaw of red and green cabbage, red bell peppers, summer squash and carrots cut into flower-shaped slices. Another day's pasta salad needed seasoning, though the addition of asparagus worked well. This company makes gloriously good large cookies--chocolate chip or carrot with oatmeal--and extraordinary brownies and strawberry tarts. Its foods are handsome and show considerable personality, whether chicken salad with walnuts and grapes or roast beef with herbed cheese on croissants, brandied chicken salad in brioche or a sesame noodle salad. The planners learned to avoid its crumbly, indifferent chocolate chip muffins, but Amber Grain's cooks are by and large very good and present food with imagination, right down to the whimsically illustrated menus that accompany their buffets. After several samples, I hired them myself to cater a party with deep-dish pizzas, an unquestionable hit. MGP CATERING 3309 Woodley Rd. NW Washington, D.C. 244-4169

Another very small caterer, MGP had the disadvantages of sometimes needing the association staff's help in carrying things from the car, and requiring a check to be ready when the food arrived. But its assets usually exceeded these problems so that this caterer became a favorite. Not only was the food often good, MGP brought handwritten menus and often potted plants for the buffet table.

MGP's dishes were interesting ideas, but the meals I sampled were erratically prepared. A seafood salad of crab, rice, capers and parsley was nicely sharpened with onion but smothered in mayonnaise. A well-constructed salad of watercress, soft-leaf lettuces, romaine, almonds and mandarin oranges was dressed too sweetly, and the french bread was flabby. Desserts were consistently good, though, whether tiny pecan tarts or date confection bars, and the meeting planners raved about MGP's breakfasts of tiny date and bran muffins and sausage souffle'.

One day's lunch, at $10.22, looked handsome in earthy pottery bowls. A fresh and intense mushroom soup started it well, a bit greasy but with lively flavor. But the main course of wild rice with curried turkey was a yellow pasty stuck-together casserole with a faint curry flavor and a slight sprinkle of wild rice in the stringy turkey. Dreadful. The meal was accompanied by boring stuffed celery with peppered cream cheese and olives, and bread sticks. A winey red fruit compote looked beautiful but tasted too sweet. Fortunately, date bars ended the meal as well as it began. RIDGEWELLS CATERERS 5525 Dorsey La. Bethesda, Md. 652-1515

The largest and most established of the caterers sampled -- and perhaps in Washington altogether -- Ridgewells provided food that was generally good, in a few instances excellent. Take, for example, a lunch that cost $6.25 a person: Quiche may be old-hat, but Ridgewells' was creamy, smooth and delicate, the custard deep and the portions plentiful. The crust was a problem, flaky and crisp on the sides but dissolved into a flour-water paste on the bottom, and the layer of ham added little flavor. Croissant-shaped dinner rolls and stuffed tomatoes completed the main course, but the hollowed-out, unripe winter tomatoes filled with frenched green beans (which tasted merely defrosted and unseasoned) were so awkward to eat with a plastic fork that half the lunchers just ate the beans out of the tomato, and one tomato remained with fork still stuck in it, its handle broken off. Desserts included a sticky, gummy chartreuse-green lime meringue pie which tasted laboratory-fresh; a spongy, dry and tasteless cheesecake, and a dark, flaky pecan pie that was so much better than the others that it immediately disappeared.

A more expensive Ridgewells' lunch at $13.12 was tender and well-seasoned beef in a home-style gravy, garnished with tiny vol au vents filled with cold vegetables in mayonnaise, more a decoration than a taste treat. What Ridgewells did exceptionally well this time around was rice salad, a dish often boring but in this case creamy, tangy and sparked with plenty of dill and onion. For dessert Ridgewells served a good fresh fruit salad and tea cookies that tasted as if somebody had misplaced the butter. Several times, Ridgewells also served stuffed shrimp that tasted more like fish cakes, rice prettily garnished with tiny wedges of lemon and a competent green salad. Repeatedly their pastries were the sort without much finesse but "a lotta taste."

Ridgewells' meals benefit from the caterer's experience -- chicken dishes tasted freshly cooked and not overdone, salads were bright and crisp, meats showed their quality whether lowly tongue or elegant roast beef. But they had all the personality of banquet food. And meeting planners complained about the caterer's indifference, feeling that Ridgewells treated them as a small account in a very big business. Food was typically brought two or more hours too early, necessitating reheating or chilling. And portions were small; after several experiences, the staff learned to increase the person count in order to have food available for the stragglers. TAKE ME HOME 3212 O St. NW Washington, D.C. 298-6818

It was interesting to watch this caterer improve. The first meal, back in February, started with tortellini soup -- dark and unclarified, overwhelmed by peppery spices so that it tasted Szechuan-Italian. The pa te' reiterated the spicy obsession. The homemade brioche was very good, and a green salad with fresh cooked green beans and mushrooms was just fine. Fresh fruit salad and chocolate chip cookies ended a lunch of home-style cooking that lacked a certain food sense in the seasoning. The cost was $7.90. Immediately following was a considerably better meal, of chicken pies, for $6.30. Prettily decorated with pastry cutouts, the pies had large chunks of chicken, scallop-edged carrot slices and zucchini--which prompted one luncher to comment on the zucchini-ness of lunches these days. All was well in the cooking of this pie, the chicken tender and the vegetables crisp, the sauce fragrant with tarragon and just thick enough to coat the meat. The crust was too thick to cook through at the edges, but it was flaky. Bread, cheese, lemon mousse (nearly delectable but too sweet) and buttery-but-tough cookies rounded out the meal. Again, lots of goodness but flaws that needed noting.

In March, a meal at $8.44, of assorted sandwiches, marinated vegetable salad, pasta salad and raw vegetables with dip repeated the seasoning excess. The vegetables left a bitter aftertaste of herbs. Spiral noodles tossed with vegetables were drowned in dill, scallions and hot pepper. And the sandwiches may have tasted too cunning to some, since they were spread with both mayonnaise and a cranberry relish. But those sandwiches were special, made with dark homemade bread and stuffed with the likes of fine smoky ham.

The association's staff had mixed feelings. The sandwiches were too large and sloppy to eat tidily, and the breakfast sticky buns were marvelous but so sticky, one person noted afterward, that "the minutes are unusable from these meetings." The catering company is so small that it sometimes ran out of bowls and had to send things in plastic containers. But it was very cooperative, and usually the presentations were lovely. One day the green bean salad was difficult to eat because the beans were too long; after a complaint, Take Me Home began to cut them shorter. And the sandwiches were made tidier, the seasonings lightened.

Thereafter, a lunch at $8.74 was excellent. Chicken canneloni was filled with large chunks of moist chicken and topped with a light, fresh-tasting tomato sauce and plenty of riccota. The seasoning was bold but not overwhelming. The vegetable salad was just right, the bread again homey and delicious. And even better was dessert, a kiwi tart with some of the tenderest and flakiest puff pastry ever, filled with a soft, creamy custard under the kiwis. A later lunch crossed chicken salad and waldorf salad with great success, and the salad of spiral noodles with julienned vegetables used the dill and garlic to advantage this time. The bread was faintly sweet and caraway flavored, and the lemon tarts light and delightfully tart. This is a caterer that learns fast. AMERICAN CAFE 1211 Wisconsin Ave. NW Washington, D.C. 337-3603

Much as the meeting planners liked the sandwich lunches of American Cafe the first couple of times around, they grew bored with the menu thereafter, and found them increasingly expensive. There was always more than enough food, often enough for lunch two days in a row; the planners would have preferred less food and lower prices. But at least the first time around, American Cafe's sandwiches and salads were immensely popular; the problem was not quality, but variety.

Depending on the size of the group, the cost ranged from $12.98 to $15.80 per person. For that price, the lunch included platters of sandwiches, a typical one being smoked turkey of excellent flavor but sliced so thin that it was dry and crumbly by lunchtime. It was served on seeded rolls with tomato and romaine (sometimes a bit sandy). Along with the sandwiches came red-skinned potato salad in an oil and vinegar dressing with a lively intensity of herbs and onion, but like the sandwiches, the potato salad suffered from standing or storage. American Cafe's fresh fruit salad has been impeccable, the best in any of the caterers' lunches. And dessert is likely to be delicious, very thin and crisp chocolate chip cookies or cheesecake. HELENE AND JAMIE 3722 S St. NW Washington, D.C. 20007 965-4238

A small company can be a problem for meeting planners if, like Helene and Jamie, it requires the staff's help in carrying things to and from the car. Helene and Jamie's prices, in addition, were considered too high. The catering firm was usually hired for buffet dinners, and they ranged from $11.55 to $13.14 a person. Often the dinners were unusual and very tasty. And always they were uniquely attractive, such as the dinner served on black paper plates with chopsticks, the food set out in baskets and lacquered trays, and the table decorated with a large paper fan.

It was cooked, however, with mixed success. Chicken tarragon had a lawnful of herb but was otherwise lacking in flavor. Carrot and red cabbage slaw tasted plain, Indonesian rice salad was chewy and heavy with garlic, not as interesting to taste as to contemplate. One day sesame noodles were nothing but noodles tossed with sesame seeds that had a bitter aftertaste as if they were rancid. Another day the sesame noodles were delicious, fresh tasting and lightly bathed in sesame oil. Helene and Jamie's typical dessert was 86-Proof Cake, a boozy chocolate bundt cake which was good but not memorable. The lime mousse, heavily flecked with lime peel and served with raspberry sauce, was much better.

The best of the dinners were grilled meats served at room temperature. Tangy and peppery marinated beef was excellent, and chicken cubes with lemon and tarragon on bamboo skewers were cooked just right. This caterer has an adventurous approach to seasonings; its cooked carrots are fiery, its salads heavily herbed, peppered and oiled. But the balance is usually maintained so that they are highly seasoned rather than overseasoned. GOOD FOOD SWAIM 3603 Wilson Blvd. Arlington, Va. 527-2095

The staff has liked this caterer but found it expensive; I found its food homey but only marginally good. A dinner, costing $9.15 a person, consisted of chicken bouillabaisse nicely seasoned with fennel but far too soupy for a buffet, and its meat was stringy. Brown rice enhanced it, as did a bright and fresh-looking tossed salad with a mild creamy dressing. Good chewy seeded rolls were the best part of the meal, a spicy sheet cake--perhaps carrot--the worst, being slightly stale and with an unpleasant aftertaste. That meal was passable, a later dinner not. Stuffed peppers topped with a browned layer of tomato sauce tasted like the standard, bland cafeteria dish, and the tossed salad showed less character than before. Again, the seeded rolls were particularly good, but the nutty coffeecake had little flavor. TRUDIE BALL'S EMPRESS 1018 Vermont Ave. NW Washington, D.C. 727-2324

Lunches ranged between $8 and $10 per person, but the menus were predictably similar. "It's a set piece," said the APA staff, "nice and basic." As one planner said, "People like it. They eat it all up." I found it typical Chinese buffet food, most of it moderately good but all of it soggy from standing. It is unfathomable why someone would serve cooked-ahead, sweet-and-sour fish on a steamtable. The fish grows fishy, the dough soggy, the sweet-and-sour sauce gummy. It becomes a ghastly dish. And stir-fried beef with vegetables loses its crispness and juiciness in the holding process. A chicken dish with cashews, peanuts and vegetables was tasteless. In all, it was average Chinese steamtable food, which means it was a damp and murky meal. WILLIAMS 623 Fourth St. NE Washington, D.C. 544-4773

Price was the draw with this caterer, even though its lasagne had left a bad taste in its wake. Portions were substantial, and the caterer would do a job on short notice. But a $6.50 price didn't compensate for salty and curdled quiche that tasted a mishmash of cheese, black olives, onions and some anonymous ground-up red meat. The salad dressing was sweet and peppery, the pepperiness attractive but the sweetness an interference. And a chocolate sheet cake was simply terrible, dry yet pasty, with a sugary pale frosting. Both the lunch and the samples at the tasting buffet looked sad and shopworn. FETE ACCOMPLIE 3714 Macomb St. NW Washington, D.C. 363-9511

Although the association found it inconvenient to use Fete Accomplie more than once because it will not deliver, its bakery products were sensational. A lunch at $6.44 was bright and colorful but otherwise unexciting, the tortellini salad with julienned vegetables nicely cooked but not noteworthy, the string beans vinaigrette with walnuts and red and green peppers fine. But the split and buttered crusty sourdough rolls eclipsed everything--until time for dessert, the crunchiest and butteriest and most delicious cookies, along with less stellar macaroons and fruit salad. THE TASTING BUFFET

From the several dozen caterers invited to bring two dishes to the American Psychological Association's meeting planners' lunch, 10 showed up. Avignone Freres accepted the invitation and called to confirm, but never arrived with any food. B & B's representative stayed around to watch what the others were bringing and subsequently called to apologize for having brought just cold cuts as an entree, and to make the point that it could do more interesting things.

While the array ranged from simple to complex, meager to lavish, three fashions were evident across the board. Tomato roses decorated one platter after another. And oranges sliced with the skin on garnished even chocolate chip cookies (thereby turning them soggy). Finally, the zigzag slicer is evidentally cutting a swath through town, at least on the business-lunch circuit.

After much tasting and discussing, the caterers were grouped into three categories: WOULD USE AGAIN

LUCKS (11403 Amherst Ave., Wheaton, Md., 949-5558): Easily the favorite, Lucks had brought the most dramatic display, a platter of chicken and pineapple salad, both in large chunks, topped with toasted sliced almonds and a tomato rose. Fat asparagus wrapped in pimiento strips, lovely looking deviled eggs and zigzag-cut oranges decorated that platter. Even more gorgeous was a fruit arrangement of 3-inch strawberries, zigzagged kiwi halves, melon balls and pineapple spears in a basket. It all tasted at least as good as it looked; the chicken salad was a mite sweet, but very fresh, crunchy, creamy and well seasoned. The asparagus had been peeled and cooked tender-crisp. And the fruits were ripe and fragrant.

MGP (3309 Woodley Rd. NW, Washington, D.C., 244-4167): Hot zucchini soup with parmesan was earthy and rich, unusual and well received. And a salmon tarragon mold, in a fish shape and decorated with watercress, looked dried out but tasted soft and creamy. Homemade brown bread didn't mate well with the salmon mousse, but it was sweet, spicy and delicious.

CHEZ WOK (1015 Wisconsin Ave. NW, Washington, D.C., 333-9220): The most unusual dish drew some wariness at first, but eventually it was accepted and praised highly. The dish in question was chicken in a creamy pink sauce with strawberries. The chicken was perfectly tender and moist, the sauce as creamy and buttery as beurre blanc and delicately herbed, the strawberries a surprise of fragrance but adding a complementary tartness rather than sweetness. The wild rice accompaniment had grown pasty in the chafing dish and was quite salty, but it was a generous addition -- decorated with a tomato rose.

AMERICAN AMBER GRAIN (1414 Q St. NW, Washington, D.C., 667-0843): This time around, Amber Grain's food looked bland, but had plenty of sparkle in the tasting of it. Tortellini salad was the favorite because of its spicy filling, crisp green beans and creamy dressing with a kick. Meat and vegetable pies in puff pastry had unusually crisp and fresh fillings, but the dough dominated. MIGHT USE AGAIN

SUZANNE'S (1735 Connecticut Ave. NW, Washington, D.C. 483-4633): While the food looked handsome, with a personalized touch, it tasted uneven. Almost everybody disliked the artichoke pie; its crust was flaky and good, but the filling had an unpleasant acid, metallic taste. One meeting planner complained that when you order a quiche from Suzanne's you have no say in what kind you'll get; you just get the "quiche of the day." A meat platter of excellent homey-looking cold cuts with spiced olives and home-style breads was attractive, and a red-skinned potato salad with capers and a horseradish bite would have been delicious if the potatoes had not been undercooked. A pristine spinach salad with red onions and mushrooms was refreshing. But the hit was a dark chocolate cake with a light, alcoholic mousse filling.

SUTTON PLACE (3201 New Mexico Ave. NW, Washington, D.C. 363-5800): A meat platter of carefully rolled-up rare roast beef and smoked meats looked so dried out that nearly nobody touched it, and the basket of flabby rye and pumpernickel was no more tempting. A mushroom-garnished potato salad was also dried out, grainy and sweetened as well. But dessert was a lovely fruit platter and huge cookies that were marvelous, even though slightly soggy from their garnish of oranges and strawberries. WOULD NOT USE AGAIN

CONNECTICUT AVENUE (6303 Georgia Ave. NW, Washington, D.C. 20011: The platter of rare roast beef, turkey, ham and salami was carefully arranged but didn't mate well with its garnishes of maraschino cherries, pineapple, cranberries and tomato roses. A potato salad was all right, macaroni salad was too sweet, an antipasto platter was pedestrian. There were cheeses, decent little fruit tarts and pretty but dull chocolate mousse. In all, it was a generous array but with little imagination and nothing memorable.

B & B (7401 Blair Rd. NW, Washington, D.C., 829-8640): Cold cuts--well-done roast beef, turkey roll and the like, with tomato roses--were mundane, ditto the fruit salad and halved eggs. The potato salad was dry looking and sweet tasting, and fruit tarts runny. The best of the lot were the beef and the onion rolls. B & B had underestimated its competition.

UPSTAIRS DOWNSTAIRS (1720 H St. NW, Washington, D.C., 298-8338): Four-inch-high triple-decker sandwiches looked monumental but were impossible to eat, and their meat was dried out. A mushroom beef barley soup was like double-salted bouillon. The rest of the generous but unexciting array was raw vegetables with dip, a salad platter, cubed cheeses and fresh fruit and a dense and nutty, perfectly adequate carrot cake.

WILLIAMS (623 Fourth St. NE, Washington, D.C. 20002, 544-4773): So pleasant have planners found this caterer that they have been willing to accept unattractive-looking platters of tomatoes stuffed with very sweet tuna or with cheese and tasteless mixed vegetables, or chunks of roast beef and fresh asparagus, a nice combination undone by a bland yogurty dressing. Some qualities eclipse the food itself in a workaday world.