Nature still holds back a few of her treasures to be enjoyed only during a brief "season." One, of course, is shad roe and shad itself. (Canned shad roe do exist, but not for me.)

The shad is a bone-filled fish and for that reason the seemingly excessive price for boned fillets may represent a bargain in terms of eating pleasure. Broiled until firm but not dry and attended on the plate by no more than a generous dollop of anchovy butter and a wedge of lemon, [WORD ILLEGIBLE] fillet (or a portion of one as they tend to be large, rich and filling) represents a case study in perfect simplicity or, if you prefer simple perfection.

As for shad roe, only the most sadistic or most innocent of cooks would subject it to such high and prolonged heat that it becomes tough, dry and gray-brown. Cook it gently in a covered frying pan, basting with butter, turning it once and seasoning the finished product only with salt, a grind or two of pepper and lemon juice.

These preparations, which hardly require more formal directions, suffice during the short season. Here is a recipe by Kenneth Lo, whose series of Chinese cookbooks are among the best in the field. KENNETH LO'S RED-COOKED SHAD (Serves 4 to 6) 1 shad, 4 to 5 pounds 3 tablespoons soy sauce 1/4 cup sliced a bamboo shoots 1 tablespoon sugar 3 tablespoons sherry 1 teaspoon salt 1 tablespoon chopped fresh ginger root 1 tablespoon chopped union 1 cup dried Chinese mushrooms, soaked in 1 1/4 cups water 3 tablespoons lard 1 tablespoon cubed fatback 1 tablespoon cornstarch

Remove - or have fish market remove - head and fins of shad and cut it in half lengthwise. (Buying a smaller shad and using both halves won't do - too many bones, so interest a friend in doing the same recipe and split the fish). Clean and soak in water for 1 hour.

Dry fish and rub scale side with half the soy sauce. Mix remaining soy sauce, bamboo shoots, sugar, sherry, salt, ginger, onion, mushrooms and mushroom water in a bowl and set aside.

Heat lard in a skillet. Fry fatback for 2 minutes. Spread cubes around skillet evenly and plate fish on top of them, scaleside down. Fry without stirring for 5 minutes. Turn fish over and fry on other side. After 1 minute, pour off excess lard and add soy sauce mixture. Lower heat and simmer until cooked, about 15 minutes.

Lift fish out onto a plate. Turn heat to high and add cornstarch, blended with a little water, to fish liquid. Bring to a boil and stir for 30 seconds until sauce thickens. Pour sauce over fish and serve.