A special French method of cooking duck at home

If you buy a frozen duck, it often comes with the simple cooking instructions to put the bird into a moderate oven and roast it for 2 1/2 hours or so.

The result may be edible but it is far from what roast duck can be. Cooked too long, a duck can be on the dry side while, paradoxically, its skin is generally not as crisp and brown as it should be.

Many restaurants serve ducks by cooking them in advance and putting the individual servings under the broiler as they are ordered. That yields a crisp skin, but again the flesh is overcooked and dry or even stringy.

Some restaurants, on the other hand, serve amazing brown, crisp ducks with moist succulent flesh.

Some years ago I asked the chef of one of these restaurants, Andre Soltner, owner of New York's Lutece, how he did it. ''My only comment,'' he said, ''is that it works very well but makes a lot of smoke, so if you have an exhaust fan use it, or leave the windows open.''

Dry the duck thoroughly and brown it in a heavy skillet over a medium-high flame. Be sure that all surfaces are browned. The whole operation will take a good 20 minutes, in the course of which a great deal of the bird's fat will run off.

It can be poured off as it accumulates in the skillet. Save it, incidentally: It is good for frying potatoes or potato pancakes. This browning can be done some little while in advance.

Now put the duck on a roasting rack into an oven preheated to at least 500 degrees F., even 550 if you have the courage. Leave it to roast for 45 to 55 minutes, and that's that. A fat-free, crisp, moist bird, and in half the time.

Paris's La Tour d'Argent has made its reputation on a single dish: its pressed duck. That excellent dish makes use of the two ends of the duck in two different ways: the whole bird is par-roasted, the breast meat is carved and its cooking finished in a sauce made from the crushed carcass and an array of other ingredients.

After the breast meat has been eaten, the legs are served as a separate course, simply broiled. One duck for two people, but two very different preparations from one duck.

The recipe I am going to include here outlines only one of the many possibilities for flavorings and garnishes. Duck Dinner For Two 1 duck, fresh, not frozen Vegetable oil 2 medium carrots 1 stalk celery 1 large onion 2 cloves garlic 6 black peppercorns Parsley Thyme Salt and pepper 3 tablespoons vinegar (see recipe for types) 6 tablespoons unsalted butter

The first thing is to remove the two breast cutlets, leaving the skin intact on each, and then to remove the legs. Your butcher or poulterer might be asked to do this if you are fearful of doing less than a neat job. Ask him to give you all the fat and the carcass and giblets as well as the two legs and two steaks.

Chop up carcass and make some brown duck stock. Brown bones, gizzard, neck and heart in a little vegetable oil. When they are a good brown color add carrots, celery, onion and garlic, all chopped coarsely, cook. Add peppercorns, a good third of a bunch of parsley, and half a teaspoon of dried thyme into pan and add water to cover. Bring to the boil and let stock simmer for about an hour , skimming occasionally, especially for the first 20 minutes or so.

Strain stock and set aside, then at some point before using it skim off as much fat as possible. If there is time, chill stock, let fat solidify in a layer on top, which will make it easy to remove.

About an hour or so before dinner time, put the duck legs into the oven to roast. Tie a loop or two of string around thighs to keep them a nice compact shape, prick skin in a few places and put legs on a rack in an oven preheated to 400 degrees F. You may salt them before or after cooking. Afterward makes more sense, however, as the exuding fat will rinse away much of the salt during roasting. The legs can roast for a good hour: by some standards they will be overcooked, but the skin will be crisp and the meat tender.

Allow about 20 minutes for preparing the duck steaks and their sauce. Prick the skin of the breasts all over and dry them carefully. Heat a very little bit of oil in a heavy skillet and put steaks in, skin side down, over high heat. After a minute or so, when skin has begun to brown, turn down heat to medium-high and let steaks cook for about 3 or 4 minutes longer. Turn them over and cook on other side for a similar time. You may use the time of turning over to pour off some of the fat. The steaks are best when rare and a shorter cooking time than I have given might be a good idea. The matter of doneness is very personal, however, and I can say only that the duck steaks should be cooked as long as you would cook a beefsteak of similar size.

Keep steaks warm on a covered plate. Add vinegar to skillet, from which you have poured off fat. The vinegar can be any of several kinds. I have used the raspberry-infused vinegar from France with success. Last summer, I pickled some sour cherries and the last time I did this dish I used the cherry-and-spice-scented vinegar from the crock with even greater success.

Alternatively, a first-class wine vinegar will be nice, as will a superior grade of cider vinegar. When sauce is finished, you can add some suitable fruit to it: raspberries if in season, or if you use cider vinegar, sauteed apples would be nice. Use a wooden spoon to stir vinegar about over medium-high heat, scraping up bits of meat or juice sticking to pan.

Reduce vinegar down to less than a tablespoonful and add a cup of duck stock. Boil it down hard to around 2 tablespoonsful. Keeping heat fairly high, add 6 tablespoons butter in one piece. Whisk sauce with a wire whisk. As butter melts, it will be incorporated into the reduced stock and vinegar, thickening the sauce without the need for any starches. You can now strain the sauce and if you like add any appropriate fruit.

To serve, you have two basic options. What I do is to serve one single course in this way: Slice each duck steak on the bias into 1/4-inch slices and arrange slices, overlapping, in a crescent, on one side of the hot plates. Down the middle, place some sauteed potatoes, possibly cooked in the rendered duck fat; then the crispy roasted duck leg on the other side of the potatoes. Spoon some of the sauce over each of the sliced breasts and serve.

If you do not mind washing an extra couple of dishes, you can serve the breast steaks and potatoes first, followed by the legs and a simple green salad.