NEARLY EVERYONE has heard of "Canard a l'Orange," or duck with orange sauce. Magnificent when done properly, it is too often over-cooked and plastered with a bitter-sweet, orange-marmalade forgery of a sauce.

Another popular preparation is Peking Duck. Few of us have the equipment to execute properly this dish, with its moist brown meat that seems to come as an afterthought to the glistening crisp, chewy skin.Much less well known are methods of braising or stewing duckling which result in exceptionally fine sauces with tender flavorful, nearly fat-free meat.

The ready-to-cook duckling found in grocery stores is a breed called Pekin. All domesticated ducks, with the exception of the Muscovy, are descended from the wild mallard. This breed was introduced into the United States from China in 1873, and it is the only one used for commercial duck raising here. (The Muscovy or Brazilian duck is a native of Brazil and is considered a different species.) The Pekin duck is an efficent producer of meat, and at 12 weeks it weighs about six pounds, or 50 times its initial weight. For classification purposes, any bird much bigger than six pounds is no longer a duckling, but I have never seen one weighing over six pounds in any market for sale.

Duck has a bone structure slightly different from that of a chicken. There is more bone in proportion to meat, so it is necessary to purchase at least one pound of dressed duck for each person you plan to serve. All the meat is dark, and the thighs are as ample as the breasts.

Duckling is usually found in the frozen poultry section of supermarkets, although some fresh duck has been on sale in the past year. For best results, thaw in the refrigerator for two days, removing the giblets from the cavity as soon as possible. There will be less loss of moisture this way.

Safeway is currently selling fresh ducks wrapped the same way as frozen ones, but labeled fresh and dated. The French Market in Georgetown carries frozen Muscovy ducks as small as two pounds. This type of duck is similar to the Pekin and it thought to have somewhat less fat. Burrows Poultry at the Georgetown Market on Grace Street sells frozen duckling, sometimes as large as six pounds. William Pence, who operates a poultry outlet at 523 Morse Street NE, carries fresh ducks on Fridays and Saturdays. Prices vary widely, with Pence's lowest at $1.09 per pound.

The following recipes include a Ragout of Duckling, an adaptation of an old French way of cooking wild ducks. The skin with its fat layer underneath is removed before cooking, making the bird resemble more closely a wild duck. The sauce is plentiful and delicious and the stew should be served with fried polenta. Southern cooks will recognize this as fried corn meal mush, and there is no better accompaniment. Along with a recipe for Braised Duckling with Spring Vegetables and Duck with Apples, there is a fine version of Duck with Orange Sauce from the old restaurant Quasimodo in Paris. This recipe appeared in the book "Paris Cuisine" by James A. Beard and Alexander Watt. Note: In recipes calling for the use of stock in the sauce, first enrich the stock by cooking it for several hours with the gizzard, heart and neck obtained from the duck cavity. Strain, skim and use.

DUCKLING RAGOUT

(6 To 8 Servings) 2 ducks, weighing about 4 pounds each 1 quart chicken stock, enriched with the giblets 1 bottle dry red wine 6 large shallots, peeled and chopped 4 cloves garlic, chopped 1 medium yellow onion, chopped 2 bay leaves, crumbled 1/4 teaspoon each fennel seed, thyme, rosemary and sage (dried) crushed 6 whole juniper berries crushed 2 whole cloves 1 (2 inches) stick cinnamon Freshly grated nutmeg 1 teaspoon salt 1 teaspoon crushed black peppercorns 3 tablespoons butter 4 tablespoons cognac 1 strip orange peel 1/2 cup heavy cream 4 tablespoons madeira wine 2 tablespoons arrowroot or cornstarch

Skin the ducks. This is easily accomplished. Cut down the backbone witha sharp knife and with the fingers pull the skin and its layer of fat (they will stay together) away from the flesh, using the knife only when necessary. It comes off almost like an overcoat. Remove the backbones and cut each duck into quarters or into six or eight peices.

Make a marinade with the red wine, chopped vegetables, herbs, spices, salt and peppercorns. Place the duck pieces in this liquid, using a deep earthenware, glass or stainless steel bowl. Cover, and keep in the refrigerator for two days, turning pieces once or twice a day if necessary to keep them evenly covered with the marinade.

After two days, remove the duck pieces, reserving the liquid, dry them carefully, flour lightly and saute in the butter, over moderate heat, until light brown. Combine the unstrained marinade with the prepared chicken stock and reduce over high heat by half. Strain. You should have about 4 cups of liquid.

When all the duck has been browned, pour off any extra fat from the saute pan, warm the cognac and flame it, pouring it over the duck pieces. When the flame dies, deglaze the pan and place the duck and pan juices in a shallow ovenproof casserole. Add the strip of orange peel. Pour the reduced stock over the duck and cover the casserole. Bake in a 350-degree oven for about 1 1/4 hour.All of this can be done the day before you wish to serve it. Refrigerate the duck and sauce together. The next day remove any fat from the surface and reheat slowly.

When the duck is hot, remove the pieces to a serving dish and keep warm. Add the heavy cream to the sauce and boil for a few minues. Add madeira wine mixed with arrowroot to thicken the sauce slightly. Taste for seasoning; additional salt and pepper may be needed. When very hot, pour sauce over the duck and garnish with fresh chopped parsley if desired, and squares of fried polenta.

POLENTA

Put 1 1/3 cup white or yellow corn meal in a saucepan. Add 4 cups cold water and 2 teaspoons salt, stirring well with a whisk. Put over the heat and bring mixture to a boil, stirring rapidly and constantly. Turn the heat way down and cook for about 15 minutes. Stir occasionally. It should be very thick. Butter a shollow pan and put the polenta in it, smoothing it to a thickness of about 3/4 of an inch. Let it cool, preferably overnight in the refrigerator. Cut it into squares and fry it in butter until light brown and crisp on both sides and heated through.

BRAISED DUCKLING WITH SPRING VEGETABLES

(4 servings) 1 duck, weighing 4 to 5 pounds 1 yellow onion, sliced thin 1 clove garlic, crushed 3 large shallots, sliced 1 bay leaf 1/2 teaspoon dried thyme 1 small handful fresh parsley sprigs 1 teaspoon whole black peppercorns 1 cup chicken, veal, or beef stock, enriched with the giblets 1 cup dry white wine 1 tablespoon flour mixed with 2 tablespoons soft unsalted butter for thickening 8 tiny white turnips (or pieces trimmed to the size of a Ping-Pong ball), 8 carrot pieces, 8 little new potatoes also trimmed to the same size, 8 little white onions, all cooked rapidly until tender but still firm 2 tablespoons sweet butter 2 teaspoons sugar Salt and freshly ground pepper

In an oval roasting pan, place the prepared onion, garlic and shallots, bay leaf, thyme, parsley and pepper-corns in the center so that they will be covered by the body of the duck. Place the duck on this bed of vegetables and roast in a 400-degree oven for 45 minutes. Pierce the skin of the duck two or three times to help release the fat that lies under the skin. Do not cover.

Remove the duck at the end of the cooking time, pour off all the accumulated fat and add the prepared stock and the white wine. Return the pan to the oven and continue cooking, uncovered, for another 20 to 30 minutes. There will be some slight resistance to a skewer poked into the thigh joint and the juices should run a little pink. Do not overcook.

Put the duck on a serving platter and strain the cooking liquid. Remove all the fat from the top, put in a sauce-pan and bring to a boil. Lower the heat and add the kneaded ball of butter and flour (buerre manie ), stirring constantly until it dissolves. Sauce should be glossy and slightly thickened. Do not let it boil again.

Put the prepared cooked vegetables in a saute pan with the hot butter. Sprinkle with the sugar and cook, turning constantly, over high heat to glaze the vegetables. When shiny and lightly browned, arrange around the duck with small bunches of watercress. Season them with a bit of salt and freshly ground pepper if needed. Serve immediately with the sauce.

DUCKLING WITH APPLES

(4 servings) 1 duck weighing 4 to 5 pounds Fresh or dried rosemary 1 small carrot chopped 1 stalk celery chopped 1 small onion chopped parsley, peppercorns, small bayleaf 1 1/2 cups chicken stock Gizzard, heart, neck from the duck 2 cups bottled hard cider, either French or English 4 to 6 tablespoons Calvados (French apple brandy), domestic Apple Jack or Cognac 2 large Golden Delicious apples 3 to 4 tablespoons sweet butter Salt, freshly ground pepper to taste 2 to 3 tablespoons red wine vinegar Arrowroot Watercress for garnish

Crush 1/4 teaspoon of dried rosemary in a motar, or chop fine the leaves stripped from one 6-inch stalk of fresh rosemary (reserve the stalk for the stock). In a shallow earthenware or glass dish large enough to hold the duck, put the rosemary, 1 cup of the cider and 2 tablespoons of the Calvados. Add some pepper and place the whole duck in the marinade, turning it from time to time to expose all the surfaces to the liquid. Marinate it for 2 to 3 hours at room temperature.

In the meantime, in a saucepan, combine the stalk of the rosemary (or another 1/4 teaspoon dried rosemary), carrot, celery, onion, parsley, peppercorns (about 1/4 teaspoon whole) and bayleaf with the chicken stock and the giblets from the bird. (Reserve the liver for the sauce.) Bring this to a boil, reduce the heat and simmer covered slowly for about 3 hours. If the liquid reduces below the level of the vegetables, etc., add hot water to replenish. You should have 1 1/2 cups of stock, approximately, when finished.

Cut the apples in half, peel and core them. Slice them widthwise in thin slices and keeping the halves together, place them in a well-buttered baking dish. Press the halves firmly with the hand to fan them slightly and dot with additional butter. Bake in a 300 degree oven for about 40 minutes, timing them so that they will come out of the oven shortly before the duck is to be served.

Drain the duck well, reserving the marinade, and pat it dry with a paper towel. Place it in a roasting pan and roast at 400 degrees for about 1 1/4 to 1 1/2 hours, depending upon size. Do not overcook. Prick the skin of the duck at the beginning of the cooking time to allow the fat to escape. Halfway through the cooking time, it may be advisable to drain off the accumulated fat in the pan, returning the duck immediately to the oven to finish cooking.

Remove the duck from the pan and keep it warm, our off all the fat and deglaze the pan with the prepared stock, which has had the fat removed from it also. Add the other cup of cider and the reserved marinade. Boil hard, reducing the liquid to about 1 1/2 cups. Strain. Saute the reserved liver quickly in a little butter, but it in thin strips and add it to the sauce along with 2 or 3 tablespoons wine vinegar and salt and freshly ground pepper. Thicken with 1 tablespoon arrowroot mixed with a little cold water and heat thoroughly.

Arrange the apples around the warm duck, heat the remaning Calvados, or substitues, ignite it and flame the duck. You can do this at the table if you wish. Serve immeditely with a watercress garnish and the prepared sauce.

CANARD A L'ORANGE

"QUASIMODO"

(4 servings) 1 duck 4 to 5 pounds Salt, pepper 1/2 cup sugar 1 tablespoon wine vinegar Juice of 2 oranges 1/4 cup Grand Marnier Grated rind of 1 orange 1/4 cup shreds of orange peel

Clean and pick the duck. Salt and pepper it and roast in a 325 degree oven for about 1 hour to 1 hour 15 minutes, for the bird should be slightly rare. (Long Island ducklings have to be roasted in a different manner than French ducks decause they have more fat under the skin and therefore must be roasted longer and more slowly.)*(FOOTNOTE)

* I would suggest that the duck be roasted in the same manner as the duckling with apples, that is 400 degrees for 1 1/4 to 1 1/2 hours. (END FOOT)

Remove the duck to a hot platter. Skim the excess fat from the rosting pan.

Combine the sugar and vinegar in a heavy pan and let the sugar melt and just start to caramelize. Add the orange juice, the Grand Marnier and grated orange rind. Let them blend together well. Add to the juices in the pan and bring to a boil. Add the shreds of orange rind, correct the seasoning and pour over the duck.

You may garnish the platter with orange slices if you wish. CAPTION: Illustrations 1 and 2, no caption, By Terry Dale for The Washington Post