Summer cooking on the grill

He was 8, his head round, his eyebrows thick and dark, his mobile face capable of joy, sorrow, dismay and . . . resignation.

''It starts on the Fourth of July,'' he told the other children as he stood at the foot of our back steps, one sneaker on the second step and his elbow leaning on his knee.

''We have hamburgers cooked outside on the grill. Then every day the sun shines, we have hamburgers again. And when we go to the seashore for two weeks, we have nothing but hamburger. By September I look like a hamburger.''

That year they had come over to celebrate the Fourth in our backyard, and guess what? Yes, hamburgers were on the menu and hot dogs, too. Together on the grill they were the synthesis of picnic grandeur for our children.

Then everybody grew up . . . or at least their palates did. Building the fire and getting coals right was a chore, so whatever was cooked should be exciting and worth the effort. At the very least, a thick steak was grilled to ruddy redness at the center, sliced slightly on the diagonal, and the slices trapped between toasted pieces of French bread. Nothing else. A little salt and pepper.

Other possibilities were put to work, and finally we had enough to get us through those summer weekends with only an occasional hamburger.

Nothing says these must be done one at a time. New picnic grandeur could be a grill with a fire large enough to produce two or three of these hot, luscious sandwiches, and everybody can have a selection. Charcoal-broiled Chicken Heroes 3 large chicken breasts, about 1 pound each, boned 1/4 cup olive oil 1 large clove garlic, minced and mashed to a paste 1/2 teaspoon salt 1/4 teaspoon freshly ground pepper 6 individual Italian heroes 6 leaves Romaine lettuce 1 small onion, thinly sliced 6 pepperoncini or other mildly hot peppers, minced

Place each chicken breast half, with skin, between sheets of wax paper and pound to flatten to an even thickness. Combine olive oil, mashed garlic, and salt and pepper in a large platter and turn the chicken breasts in the mixture.

Cover with plastic wrap and marinate in the refrigerator for 6 hours or overnight, turning again once or twice.

Build a charcoal fire and when it has burned down to medium hot, broil chicken breasts until firm and lightly browned. In the meantime, halve heroes, pluck out some of the soft crumbs, and warm in a 300-degree F. oven for 10 minutes.

To make each sandwich, cover the bottom half of each hero with a leaf of Romaine. Add chicken, then onion, and sprinkle on a scant teaspoon of peppers. Close loaves, press together firmly, and serve to 6. Kofta in Pita Bread 2 pounds ground lamb or beef 2 onions grated 1 small egg, or 1 large egg yolk 1/2 teaspoon ground cumin 11/2 teaspoons salt 1/4 teaspoon freshly ground pepper 1 large Spanish onion or other mild onion 1/2 cup minced mint and parsley combined 4 large loaves pita bread Place ground meat in a bowl and grate onion over meat with a hand grater. Add egg, cumin, and salt and pepper and mix together thoroughly.

Shape into eight oval patties and set on wax paper on a platter. The mixture will be softer than regular hamburger.

Slice Spanish onion in half lengthwise and slice thinly in lengthwise strips. Strew onion shreds on a platter and sprinkle with mint and parsley. Cut each pita loaf in half.

Build a hot charcoal fire. Charcoal-broil kofta patties until medium done, only slightly pink in the center, turning carefully only once.

When done, arrange over the bed of onions.

At the picnic table, place 1 kofta in a piece of pita bread and add as much onion on top as possible. Steak Sandwiches Mexican Style Salsa Fria: 4 medium ripe tomatoes 1 onion, minced 1 31/2-ounce can green chilies, minced 1 canned or pickled jalapeno pepper, seeded and minced 1 1/2 teaspoons oregano, crumbled 1 tablespoon minced fresh coriander, if available 2 tablespoons lime juice 1 tablespoon vegetable oil Salt and pepper to taste 2 pounds lean, boneless steak; flank, skirt, sirloin tips 1 lime Salt and pepper 12 corn tortillas, homemade or commercial The tortillas will be eaten as though they were a slice of bread and not crisped as they are for tacos.

Prepare sauce. Core tomatoes and chop as finely as possible. Combine in a bowl with onion, chilies, pepper, oregano, coriander, lime juice, oil, and salt and pepper to taste.

Set aside for at least 10 minutes. Do not make this sauce too far ahead or it will lose its charm.

Prepare a hot charcoal fire. Squeeze lime juice over each side of steak and sprinkle salt and pepper generously. Charcoal broil until medium rare.

Remove from fire to a cutting board. While steak is being carved, heat each tortilla over the charcoal fire for a few seconds each and wrap in a napkin and place in a basket.

At the picnic table, place a slice or two of steak off center on a tortilla, cover generously with salsa fria, and roll up. As you bite into one end, tuck the other end under to save the juices. Serves 4.