Seafood is a delicious change from beef and chicken

Seafood is particularly welcome for summer meals. Not only is it light on the cook, who wants to spend as little time in the kitchen as possible, but it is a delicious change from beef and chicken.

Here are several fish recipes which demand little time and effort and are as relishing as you could wish.

First is broiled bluefish garnished with roasted peppers in brilliant red, yellow, and green. The peppers can be prepared well ahead of time, and the fish cooked at the last minute. If bluefish is not available, you may want to substitute mackerel, cod, swordfish, mako shark, salmon, or another fatty fish, either fillet or steaks. But be sure not to overcook it.

Pesto mayonnaise, redolent with basil and garlic, complements them ideally. The robust flavors of this mayonnaise marry well with other summer dishes such as poached chicken or fish, and tomato and cucumber salad.

For a busy or lazy day when you want nothing to do at the last moment, try chilled poached trout. Dress it up or not, as you choose, and make this simple dish your own by seasoning it your special way. You will find it eminently useful for any occasion, a formal dinner or a family meal.

Salmon escabeche is easier still since it requires no cooking by heat whatsoever. Thin slices of salmon are marinated in lime juice, and the acid ''cooks'' the fish in only a few minutes as you see it change color before you. Dress it with a little oil and some herbs or vegetables to serve on the hottest day of summer. Broiled Bluefish with Roasted Peppers 1 bluefish fillet, 2 to 3 pounds Vegetable oil 1/2 lemon Salt and freshly ground pepper 3 bell peppers, preferably red, yellow, and green Pesto mayonnaise (recipe follows)

Oil a large broiling pan and place fish on it. Brush fillet with oil, squeeze lemon juice over it and salt and pepper to taste. Broil fillet 10 to 15 minutes, depending on thickness, until it is just cooked through but still juicy.

Meanwhile, broil peppers until skins are blistered and singed. Remove them and when cool peel off skins. Cut out stems and seeds and slice peppers lengthwise into sections.

Arrange bluefish on a serving platter with peppers in alternating colors around it. Serve with Pesto Mayonnaise. Serves 6. Pesto Mayonnaise 2 egg yolks 1 1/2 cups oil 2 tablespoons lemon juice 1/4 cup basil leaves, minced 2 shallots, minced 3/4 teaspoon salt Freshly ground pepper to taste

In clean, dry bowl beat yolks lightly with electric beater, then add oil in slow thin stream, making sure it is well incorporated into yolks. When half of oil is used, speed up beating. Add remaining ingredients toward end and adjust seasonings to taste.

Although a blender or food processor makes good mayonnaise, in excessively hot weather I find a beater and bowl more successful. Chilled Poached Trout 4 trout, about 1/2 pound each, cleaned and scaled, but leave heads and tails on 2 leeks, white part only, cleaned and sliced 2 carrots, peeled and sliced 8 black peppercorns 2 sprigs parsley 1/2 bay leaf 1 lemon Fish stock (or clam juice) to cover Salt

Place fish in one layer in oiled, shallow ovenproof pan. Arrange vegetables and seasonings around them. Slice half of lemon across into very thin rounds and squeeze juice from other half; add both to pan. Pour in fish stock to barely cover fish. Salt to taste.

Cover pan tightly and cook in preheated 375 degree F. oven 15 minutes. Remove and allow fish to cool to room temperature. Chill before serving.

For casual meals, serve fish with leeks and carrots around them and chopped fresh parsley on top. For more elegant occasions, serve with skin carefully removed from body of fish and with garniture of fresh lemon slices. Pesto mayonnaise also goes very well with this dish. Serves 4. Salmon Escabeche 1/2 cup lime juice, or enough to cover 1/2 pound salmon fillet (not steak), bones removed 1/4 cup olive oil Freshly ground pepper Fresh chives, minced, or another fresh herb Avocado

Put lime juice in shallow wide pan. Remove any remaining bones from salmon fillet. With long, sharp knife almost parallel to fish, cut thin slices of salmon with the grain. Put them in lime juice, making sure that it covers slices. In about 10 minutes, the action of the acid will have ''cooked'' the fish, turning the salmon pale pink.

Just before serving, drain lime juice, reserving 1 tablespoon. Mix it into olive oil. Arrange salmon on serving plates and drizzle olive oil mixture over it. Grind a little pepper over each serving and sprinkle with chives. Garnish with slices of avocado and serve. Serves 4 to 6.