"THERE ARE PARTS of the country where July and August would be best spent lying in the picnic cooler with the beer," observes Elizabeth Schneider Colchie, an inventive and dedicated cook. There are few cooks--even the most passionate--who would have the energy to disagree with Colchie as the temperature rises to near boiling during August. (You know you've had it with the heat when even the thought of fresh pesto leaves you feeling limp.)

To perk up late summer wilts, Colchie and other ardent cooks challenge themselves to create summer foods that whet the flagging appetite without dissolving the cook.

Colchie, author of the recently published "Ready When You Are: Made-Ahead Meals for Entertaining" (Crown, $15.95), believes that made-ahead meals are especially valuable in the summer so that steamed-up homes can cool down before guests arrive. She likes to prepare food late at night or very early in the morning, making double or triple quantities of basic ingredients that can be served in a number of different guises at subsequent meals.

Colchie finds that the most successful summer dinner is one made up of several courses composed of lively textured, colored and flavored foods. "To provide form and focus for hazy taste buds," she claims, "nothing could better fill the bill than a main-dish salad, with appropriate accompaniments."

A typical summer menu for Colchie might be cold cucumber soup followed by a salad of shellfish and buckwheat noodles, served with Japanese or Thai beer, and fresh pineapple with almond cookies for dessert. Alternatively, she might serve a squid salad with grilled peppers, red onion, and olives (see recipe), accompanied by Italian bread with chilled pinot grigio to drink, and sliced strawberries and peaches with rum and sugar for dessert.

For inventive main-dish salads, Colchie likes to keep on hand cracked wheat because it needs no cooking (see recipe). "Like rice," she says, "there's almost nothing it doesn't go with." She also likes to have fresh herbs at hand because they "perfume" everything. "I don't think there's anything better in summer than grilled skinned peppers with any herbs in the book and a couple of tablespoons of good olive oil dribbled on top," she adds.

Colchie likes to keep a variety of See COOKS, K6, Col. 1 Warm Weather -COOKS, From K1 cooked beans--such as chickpeas, navy or white--on hand in the freezer for tossing into summer salads. She also stocks a wide assortment of oils and vinegars for impromptu salads. "You can mix and match these," she says, "change them like musical chords, depending on what ingredients you include in the salad." Preferred oils include strong and light olive, corn, peanut, hazelnut and oriental sesame. For vinegars, Colchie alternates cider, red and white wine, balsamic and sherry.

When planning a summer salad, Colchie cautions: "Avoid the everything-but-the-kitchen-sink approach. The freshness of greens, the toasty flavor of nuts, the succulence of poached fish, the tartness of an unexpected fruit--all are lost if diverting flavors and textures vie for dominance."

"And remember," she said, "you needn't do too much futzing around. Nature does the presentation in summertime."

Nika Hazelton, author of almost two dozen cookbooks and countless food articles, worries that in the summer many people feel too hot to bother about eating properly. "You must have at least two good meals a day," she admonishes, and advocates keeping an interesting selection of cheeses on hand for healthy, impromptu summer salads.

"Keep it simple and light," she says. "A lively salad of fresh assorted greens, tomatoes, radishes and diced cheese with a simple herbed vinaigrette for an entree, preceded by a cold soup and accompanied by bread and wine make a fine summer meal." For dessert she sets out a bowl of fruit and some cookies.

Aside from pesto, Hazelton thinks that cold pasta salads are "an abomination." "How can people serve a tortellini salad?" asks the author of "The Regional Italian Kitchen" (Evans, $7.95). "The pasta stuffing will congeal when cold and it just doesn't taste right. Italians never make that kind of salad.

"Go out of your way for fresh herbs in the summer," says Hazelton, "but I'm against using too many different herbs in any one dish. The flavors get terribly mixed up. The most memorable dishes are the simple ones, like a dish of spaghetti with an uncooked sauce of tomatoes, fresh basil and olive oil. And don't stint on the olive oil," she adds. "The Tuscan olive oils--the ones that cost about $20 a bottle--are wonderful and really make a difference in the taste of your sauce . . . A bottle will last a long time."

On steaming hot days, Hazelton is not beyond popping a frozen Stouffer's or Lean Cuisine dinner into the oven. "It's for an emergency, when I just don't feel like preparing anything," says the author of "American Home Cooking (Viking, $14.95). "I think people get too agitated about perfection in the kitchen. It is not the purpose of home cooking to reproduce restaurant cooking. Home food should be the things that people can't find well-prepared outside, like a really fine all-American chicken salad see recipe or a blueberry pie."

Nora Ephron hasn't written any cookbooks, but she does a good deal of home cooking, as everyone reading her best-seller, "Heartburn," will surmise. Heartburn (Knopf, $11.95) is the story of Rachel Samstat, a cookbook writer who spends so much time perfecting her peach pie (see recipe) that she forgets to pay attention to her failing marriage.

Ephron loves to cook, especially during the summer when she moves from her Manhattan kitchen with its "twelve inches of counter space" to a spacious, well-equipped kitchen on eastern Long Island. The beautiful tomatoes, corn and fresh fish she can get there inspire Ephron to give dinner parties.

For group entertaining in summer, she prefers to barbecue, "so I don't have to cook alone. Women don't ever have to do the barbecuing, do they?" One of Ephron's favorite meals includes a whole striped bass, pierced with slivers of garlic, stuffed with a sprig of fresh rosemary, rolled in oil, and grilled over charcoal. "Don't ever put the hood down over the grill," she advises. "It makes everything taste like ham."

Ephron enjoys inventing dishes from whatever is on hand. With leftover bluefish, she might design a salad including chopped shallots, minced parsley and sliced, boiled potatoes. She tosses these with the flaked fish in a vinaigrette thickened with mayonnaise.

"Another thing I love to do in summer," she says, "is chicken salad." One day Ephron might add curry powder to the mayonnaise and stir raisins and mango chutney into the whole mixture. Other times she tosses the poached, diced chicken with sesame noodles. "One of the salads I like best," she adds, "is shredded chicken with chopped lettuce and a vinaigrette with fresh gorgonzola cheese. It doesn't sound very good, but it's really a great salad."

Here are some of the favorite summer recipes of the three cooks: ELIZABETH SCHNEIDER COLCHIE'S SQUID SALAD (4 servings) 1 1/2 pounds small, cleaned squids 1 bay leaf 1 teaspoon coriander seeds 1/4 teaspoon fennel seeds 1/2 teaspoon dried thyme 1 small onion, halved 1 celery stalk with leaves, sliced 1/2 teaspoon black peppercorns 2 garlic cloves, peeled 1/2 teaspoon plus 1/8 teaspoon salt About 1/2 cup lemon juice 1 1/2 cups water 1/4 cup plus 2 tablespoons olive oil 2 medium-large, straight-sided red bell peppers 2 medium-large, straight-sided green bell peppers 1 teaspoon vinegar 1 very small head chicory, washed, dried and slivered 1 small red onion, thinly sliced and separated into rings 1/3 cup pitted, sliced, oil-cured black olives

Cut the cleaned squid mantles across into rings 1/8- to 1/4-inch thick. Divide the tentacles into manageable mouthfuls, or cut them in pieces if they are large. Set aside.

In a 2- to 3-quart saucepan, combine the bay leaf, coriander seeds, fennel seeds, thyme, onion, celery, peppercorns, garlic, the 1/2 teaspoon salt, 1/3 cup of the lemon juice, the water and the 1/4 cup oil and bring to a boil. Cover and boil gently for 15 to 20 minutes.

Strain the stock and return it to the saucepan. Add the squid and simmer for about 1 minute, stirring, until the squid is curled at the edges. Remove the squid to a bowl with a slotted spoon. Boil the liquid to reduce it to 1/2 cup. Add to the squid. Cool, cover and refrigerate.

Place the peppers directly in the flame of the gas burners of your stove (or as close to the broiling element as possible, if you don't have a gas stove). Keep turning them in the flames until they are blackened all over. Set aside for a few minutes, then place them in a plastic bag and let stand for 15 to 20 minutes. Remove the peppers from the bag and halve them lengthwise. Scrape off the stems, seeds, ribs and skins. Rinse. Cut each half into eighths, lengthwise. Rinse the peppers and pat them dry.

Combine 1 tablespoon of the oil, the 1/8 teaspoon salt and 1 teaspoon vinegar in a bowl. Add the pepper strips and refrigerate until serving time--which can be up to 24 hours later.

To serve: Arrange the chicory on a large serving platter. Toss the squid with about 2 tablespoons lemon juice, 1 tablespoon oil and pepper to taste (this dish can stand plenty of it). Arrange over chicory with the pepper strips, onion rings and olives. ELIZABETH SCHNEIDER COLCHIE'S CRACKED-WHEAT SALAD (8 servings) 1 1/2 cups cracked wheat (also called bulgur or wheat pilaf) 5 to 6 cups hot tap water 2 teaspoons salt 1/2 cup plus 2 tablespoons lemon juice 8 tablespoons olive oil 1/2 to 1 cup chopped red onion (about 1 small onion), to taste 1 cup finely minced fresh parsley 2 medium-small avocados, peeled and cut into 1/2-inch cubes 1 cup sliced red radishes 2 cucumbers, peeled and sliced (seeded, if large ones) Small whole radishes for garnish

Combine the wheat and hot water in a bowl and let stand for 30 minutes to an hour, or until the grains are no longer hard at the core. Time will vary, depending upon granulation. The grains should be firm-tender, not crunchy. Pour into a sieve lined with fine-mesh cotton cheesecloth and let the water drain out. Squeeze the wheat in the cloth to extract all the liquid. Spread the wheat on a towel and toss it to dry and separate the grains somewhat.

In a small bowl, combine the salt and the 1/2 cup lemon juice. Stir to dissolve the salt. Add 6 tablespoons of the olive oil.

In a large bowl combine the wheat, lemon and oil mixture, onion and parsley and toss thoroughly. Cover and refrigerate for several hours or more.

No more than 2 hours before serving, cut up the avocados and toss with the 2 tablespoons lemon juice and remaining oil to coat the pieces thoroughly, mixing very gently to avoid mushing the avocados. Let stand, covered, until ready to serve.

To serve: Add the sliced radishes to the wheat mixture and mix well. Add the avocado and mix gingerly. Mound in the center of a platter and surround with the cucumbers and radish garnish. COLCHIE'S ICY MINTED GAZPACHO (9 to 10 servings) 1 1/2 cups soft, white bread crumbs (about 4 slices bread, crusts removed) 1 or 2 large garlic cloves, pushed through a press 1 1/2 teaspoons ground cumin 1/4 cup red wine vinegar 1/4 cup olive oil About 1 1/4 teaspoons mild pure chili powder, also called ground mild chilis (or substitute a big pinch of cayenne) 1 tablespoon coarse (kosher) salt 5 large, ripe tomatoes (about 1 3/4 to 2 pounds) 1 cup lightly packed, coarsely chopped fresh mint leaves (about 1 good-size bunch) 1 medium-large red onion, coarsely chopped 2 medium-size red bell peppers, chopped 2 medium-size cucumbers, peeled, seeded and cut into chunks 1 tablespoon tomato paste About 3 cups cold water

Tomato juice frozen in 2 ice-cube trays

In a large bowl, mix the bread crumbs, garlic, cumin, vinegar, oil, chili powder and salt.

Core the tomatoes and halve them crosswise. Squeeze out and discard the seeds. Chop the flesh coarsely and add to the bowl. Add the mint, onion, peppers, cucumbers, tomato paste and 2 cups water. Mix together well.

In batches, pure'e the mixture to a fine texture in blender or food processor. Press each batch through the medium disc of a food mill into a bowl after you pure'e it. Add water to create the desired consistency.

Chill the soup for several hours or more, covered. Season.

To serve: Ladle into cups with a cube or two of the frozen tomato juice in each to keep the chill. NIKA HAZELTON'S ALL-AMERICAN CHICKEN SALAD (4 to 6 servings) 1/2 cup plain french dressing (i.e. vinaigrette) 2 to 3 drops hot pepper sauce (optional) 3-pound chicken, cooked, skinned and cubed (4 cups meat) 2 cups thinly sliced celery, white part only 1/2 cup walnuts, broken, not chopped, into pieces 2/3 cup mayonnaise, or to taste 1 cup seedless grapes, stemmed, washed and dried Shredded salad greens 2 hard-cooked eggs, sliced

Combine the french dressing with the hot pepper sauce (if used) and mix well. Put the chicken into a bowl (do not use aluminum) and stir in the dressing. Mix well. Refrigerate covered for 2 to 4 hours, stirring once. Add the celery, walnuts and mayonnaise and mix well. Pile in a mound on a serving plate. Stud salad with grapes. Surround the base of the salad with shredded salad greens and top these with egg slices. Serve immediately. NORA EPHRON'S FAVORITE PEACH PIE (Makes a 9-inch pie) For the crust: 1 1/4 cups flour 1/2 teaspoon salt 1/2 cup (1 stick) chilled butter, cut into bits 2 tablespoons sour cream For the filling: 3 egg yolks 1 cup sugar or less to taste 2 tablespoons flour 1/3 cup sour cream 1 pound (about 4 medium-sized) ripe peaches, peeled and sliced

Place the flour, salt, butter and 2 tablespoons sour cream into the bowl of a food processor and pulse until a ball is formed. Pat the dough into a 9-inch buttered pie tin and bake at 425 degrees for 10 minutes. Remove from oven. Reduce temperature to 350 degrees.

In a bowl, beat the egg yolks slightly and stir in the sugar, 2 tablespoons flour and 1/3 cup sour cream. Arrange the sliced peaches on the pie crust and spoon this mixture on top. Cover the pie tin with foil and bake at 350 degrees for 35 minutes. Remove the foil and bake until the filling is set, about 10 to 15 minutes.