AMERICANS prefer foods piping hot or ice cold. Elsewhere, probably because refrigeration and cooking equipment have not been as readily available as they are here, serving food at room temperature is common practice. The Greeks prefer their pastichio, the British their scotch that way.

With the introduction of nouvelle cuisine in this country, the idea of eating food cooled, or warmed, to 70 degrees has become fashionable. That's our gain. Many foods are at their best when served at room temperature. Think about the best tomatoes you ever ate . . . plucked from the vine and warmed by the sun; brie that has been sitting our for an hour. Bread, hot from the oven, smells wonderful, but the flavor doesn't come out until the bread cools down. Cold and hot dull the taste buds.

Of course, Americans have another hangup about room-temerature food, and that has to do with safety. "Keep hot foods hot, above 140 degrees; keep cold foods cold, below 40 degrees," is the slogan preached every summer. That excludes room temperature for a lot of things, things that will spoil. What it really means is, don't take the chicken salad to the picnic in an unrefrigerated container and let it sit in the hot sun for two hours. It doesn't mean you can't safely take the chill off most foods or let them cool down a bit before serving. Taking the chill off or cooling down means allowing something to sit on the counter for 15 to 30 minutes. It won't spoil in that period of time if you serve it right away.

Some of these warm-weather dishes will develop more flavor if they have a chance to sit a bit. TANGY RICE SALAD (4 to 6 servings) 4 cups cooked rice 1 tablespoon vinegar 1 teaspoon lemon juice 1 tablespoon salad oil 2 teaspoons or more curry powder 1/4 teaspoon turmeric 3/4 cup raisins 1/3 cup chopped green pepper 2/3 cup plain yogurt or sour cream 2/3 cup mayonnaise

Sprinkle hot rice with vinegar, lemon juice and oil. Mix lightly; add curry and turmeric and blend. Stir in raisins and green pepper. Add yogurt and mayonnaise; mix well. Place in 6-cup mold and chill. Either unmold to serve or heap on a lettuce-lined plate and let sit at room temperature for about 10 minutes.

%CHICKEN PINEAPPLE SALAD (8 servings) 2 3-pound chickens, cut up Few sprigs parsely 1 lemon, sliced 1 medium onion, sliced 2 stalks celery 1 teaspoon dried dill weed 3 cups cubed, fresh, ripe pineapple 1 cup chopped water chestnuts 1/2 cup mayonnaise 1/4 cup sour cream or plain yogurt Salt and white pepper 1 small clove garlic, minced 1 teaspoon celery seed 1/2 cup toasted, slivered almonds

Cook the chicken in water to cover with parsley, lemon slices, onion, celery and dill, until tender, about 30 minutes. Cool in broth, then skin and bone chicken. Cut meat into bite-size pieces and toss chicken with all of remaining ingredients but almonds. Chill. To serve, remove from refigerator 10 minutes before serving and arrange on a bed of greens. Sprinkle with toasted almonds. ARMENIAN SALAD (8 servings)

As an alternative to a cold rice salad, bulgar is a delightful, nutty alternative to mix with salad ingreidents and shrimp. 1 cup bulgur 1/2 cup oil and vinegar dressing 2 tablespoons diced green pepper 1/4 cup chopped chives 1/4 cup diced celery 12 cured-in-oil black olives, pitted and halved 1 1/2 pounds cooked, clean shrimp, halved 12 cherry tomatoes, halved 1/4 cup mayonnaise or 2 tablespoons mayonnaise and 2 tablespoons plain yogurt Salad greens

Cover the bulgur with hot water and allow to stand for about 30 minutes, until liquid is absorbed and grains are tender. Pour dressing over bulgar. Refrigerate at least 1 hour, or overnight, so that flavors blend. Mix with green peppers, chives, celery, olives, shrimp and tomatoes. Carefully mix in mayonnaise/yogurt and serve on salad greens. CHICKEN WITH TUNA SAUCE

This dish is a variation on the Italian vitello tonnato, veal with tuna. 4 large chicken breasts, halved and skinned 1 1/4 cup dry white wine 1 onion, finely chopped 1 clove garlic, minced 7-ounce can tuna 6 flat anchovy fillets, finely chopped Salt and freshly ground black pepper to taste 1 teaspoon grated lemon rind 1/4 cup good quality olive oil 3 tablespoons lemon juice 6 tablespoons mayonnaise 4 cups cold, cooked rice 1/2 cup capers 3 tablespoons minced parsley 2 pints cherry tomatoes 1 lemon, sliced Combine the chicken, wine, onion, garlic, tuna, anchovies, salt, pepper and lemon rind in a large, heavy saucepan. Cover and bring to boil; simmer gently about 25 minutes or until chicken is tender. Slice chicken meat into large oval pieces, discarding bones. Transfer to bowl. Puree the sauce in which chicken cooked, in a food processor, blender or food mill. Add olive oil, lemon juice and mayonnaise.Pour over the chicken and cover. Refigerate overnight.

To serve, remove chicken from refigerator 30 minutes before serving. Place chicken on top of rice. Spoon sauce over all and sprinkle with capers and parsely. Surround with tomatoes and lemon slices. HOT POTATO SALAD (8 servings)

Hot potato salad isn't really hot. It should be warm or you will lose the flavors in the heat. 2 tablespoons butter 1 cup thinly sliced celery 1/4 cup sliced green onions 2 tablespoons flour 1 tablespoon sugar Salt and freshly ground black pepper to taste 1 teaspoon paprika 1 teaspoon dry mustard 1 cup milk 1/4 cup white wine vinegar potatoes with skins 4 cups sliced, boiled new potatoes with skins 1/4 cup diced green pepper 1/2 cup sour cream 4 slices nitrite-free bacon, fried crisp, drained and crumbled (optional)

Saute the celery and onion in the butter until tender. Combine the flour, sugar, salt, pepper, paprika and mustard and add to cooked mixture. Gradually stir in milk and cook until thickened. Stir in vinegar. Add the potatoes and green pepper and stir carefully to coat well. Remove from heat and stir in sour cream. Spoon into serving bowl and sprinkle, if desired with bacon. PIQUANT TONGUE (3 servings)

If you've ever wondered what to do with leftover tongue after you've served it either hot for dinner or sliced as part of a cold cut platter, this is a wonderufl answer. 3 cups cooked, pickled tongue, cut in slivers or pieces 2 flat anchovy fillets, rinsed and drained 1 tablespoon pine nuts 1 clove garlic, minced 1/2 teaspoon capers 1/2 slice white bread, soaked in water and squeezed 6 tablespoons good quality olive oil 2 tablespoons red wine vinegar Freshly ground black pepper

Combine anchovies, pine nuts, garlic, capers and bread. Either pound to a paste with mortar and pestle or puree in blender or food processor. Add the oil and vinegar alternately to make a smooth blended paste. Season with pepper. Combine with tongue and adjust seasonings. Refigerate until serving time, but if refigerated, allow to sit ot for 15 to 20 minutes before serving.

Note: This would be delicious with could roast beef cut in julienne strips, too. SCALLOP SALAD (4 servings) 1/2 cup dry white wine 1/4 cup water 1 onion, sliced 3 sprigs parsley 1 teaspoon dried tarragon 1 1/2 pounds sea or bay scallops 1/2 pound whole small mushrooms 12 green olives, rinsed, drained and sliced Mayonnaise to moisten

Combine wine, water, onion, parsley and tarragon in skillet. Bring to boil, reduce heat and simmer scallops, 3 to 4 minutes for sea scallops, 1 1/2 minutes for bay scallops. Cool in broth. Rinse and remove stems from mushrooms. Steam mushrooms, 3 or 4 minutes, depending on size. Drain. Combine scallops, mushrooms, olives and just enough mayonnaise to moisten. Chill for flavors to blend but remove from refigerator 10 minutes before serving. HOMEMADE MAYONNAISE (Makes about 1 3/4 cups)

This will keep 2 or 3 weeks in the refigerator. If you are going to make salads using mayonnaise you ought to have some that is good quailty. This is a compromise. The very best is beaten by hand, but this is far superior to the commercial brands. 1 egg 1 teaspoon dry mustard 1/2 teaspoon salt (scant) Dash cayenne pepper 1 1/2 cups salad oil, preferably a combination of salad and olive oil 2 tablespoons lemon juice or half lemon juice and half white wine vinegar*

Place the egg, mustard, salt, cayenne and 1/4 cup oil in blender. Blend at high speed until competely mixed. With blender still running, take off center of cover or cover itself and slowly pour in 1/2 cup of oil. After it is completely blended (it may be necessary to turn off motor and mix mayonnaise a little with scraper), blend in lemon juice throughly. Then slowly add remaining oil, turning motor off and on as necessary to blend completely.

*Note: Tarragon vinegar may also be used.