COOKING WITH fruit is a good way to liven up fall and winter menus. Apples are always popular, but pears often seem to be neglected. And what a shame. The sweet distinctive flavor of this fruit is actually enhanced by cooking -- especially when complemented by spices and other seasonings.

Pears have a long and interesting history. They were used as food as far back as the Stone Age and cultivated by the ancient Egyptians, Romans and Greeks. Homer called them "gifts of the gods." In the Middle Ages, they were extensively grown around castles and monasteries.

Around 1850, the French gentry competed to see who could produce the finest types of pears. That's one of the reasons we have so many varieties today.

Two of the most popular available in this area are Bartlett and Seckel. Bartlett, a juicy, yellow, medium-sized, all-purpose pear, is in season from mid-August until November. Seckel, a very small russet-colored pear with a rich, sweet flavor, is usually availabel from September until early December. rIt is primarily eaten raw or canned, although it is sometimes pickled or brandied.

Anjou, also called d'Ajou, is the most popular winter variety. It is a medium-sized, green to yellow pear with a buttery flesh, explaining its full French name, Beurre d'Anjou. It has a very long season -- from November until spring.

Bosc, another all-purpose winter variety, is russet-colored and sometimes called the "aristocrat of pears." It is usually available from October until January.

Pears are one of the few fruits that improve in flavor and texture when ripened off the tree because, like bananas, they contain stored starch that then converts to sugar. Also, since pears bruise less easily in the unripened state, most are sold that way.

You should choose firm, nicely shaped fruit and ripen them at home for three to five days in a dark, humid place that is not too cool. Slight skin blemishes are of no consequence. For baking and canning, use pears that are just beginning to soften, and if they are the Bartlett variety, just showing a hint of yellow through the green skins. These will stay firm and not become mushy during preparation. For pear sauce and pear jam, use fully ripened fruit.

Pears to be eaten raw are at their best when fully ripened and soft. Bartlett pears should be completely yellow. But color in the other varieties is not necessarily an indication of ripeness. MOCK-MINCEMEAT PIE (6-8 servings)

This a delicious meatless pie that is ideal for those on low-cholesterol diets. To further lower cholesterol, use an oil-based pie crust dough. By the way, the pear "mincemeat" can be substituted in any mincemeat recipe. 1 unbaked pie shell, 9 or 10 inches, or two 8-inch shells Extra dough for lattice top 2 pounds (about 5 medium) pears 1/2 cup walnuts 2 cups raisins 1/2 cup brown sugar 2 tablespoons molasses 1 teaspoon each cinnamon, cloves and allspice 1/2 teaspoon ginger 1 tablespoon grated lemon or orange peel 1/4 cup cider vinegar 1 to 2 tablespoons brandy, optional

Core and quarter pears. (It is not necessary to peel pears if you wash them well.) Put pears, nuts and raisins through food grinder or chop in food processor. (Or finely mince with a knife.) Combine remaining ingredients, except brandy, in saucepan and add fruit mixture. Mix well. Bring to a boil, then simmer 20 minutes, stirring often. Cool. (This mock mincemeat will keep several days in the refrigerator, or can be frozen.) Shortly before using, add brandy.

Spread mincemeat in unbaked pie shell. Cover with dough strips to form a lattice. Bake in the lower third of a preheated 450-degree oven for 10 minutes. Then reduce heat to 350 degrees and bake 30 to 35 minutes longer, or until crust is lightly browned. Best when served warm; can be reheated. TARTE AUX POIRES A LA GENEVOISE

This unusual tart comes from Geneva, in the French-speaking part of Switzerland. It is not only delicious, but beautiful as well. Pastry for a 1 crust, 9-inch pie 1 tablespoon flour 2 tablespoons sugar 1 teaspoon cinnamon 4 medium-sized pears 1/2 teaspoon each grated lemon and orange peel 1/4 cup raisins 3 tablespoons dry white wine (or dry sherry) 2 tablespoons cooking oil 3 tablespoons sugar 1/4 cup heavy cream

Use pastry to line a pie plate or tart pan. Prick pastry lightly with a fork. Combine flour, 2 tablespoons of sugar and cinnamon and sprinkle on top of pastry. Peel, halve and core pears. Arrange 7 pear halves, cut side down in the shell so that all the stem ends point to the center. Cut one pear half into a circle and place in the middle. With the pears in place, cut them in slices without going all the way through, so that the pieces stay joined together. Sprinkle the pears with the citrus peels and raisins. Mix the wine and oil and pour over the pears. Top with the 3 tablespoons of sugar and cream.

Place pear tart on a cookie sheet and put in the lower third of a preheated 400-degree oven. Bake for 20 minutes, then reduce heat to 350 degrees and bake another 25 to 30 minutes, or until crust is golden brown. Alow to cool slightly. Then, if tart pan was used, remove outer ring. Serve warm or cold. Store in refrigerator. GINGER PEAR SAUCE (4 cups) 2/3 cup water 1/4 cup sugar 3/4 teaspoon ground ginger 4 cups fully ripe, finely chopped winter pears (about 8 medium)

Put all ingredients except pears in a medium saucepan over medium heat. Add pears. Bring to a boil, stirring. Reduce heat. Cover and simmer 25 to 30 minutes. Serve as you would apple sauce. SPICE PEAR JAM (6 1/2 cups) 4 cups peeled, cored and finely chopped pears (about 3 pounds) 1 tablespoon lemon juice 1 box (1 3/4 ounces) powdered fruit pectin (sure-Jell) 5 cups sugar 1/2 teaspoon ground cinnamon 1/2 teaspoon ground cloves

Although this is a cooked jam, we like to store it in the freezer, since preparation is simplified.

Wash jam jars and lids in dishwasher or with very hot water and set aside.

Place prepared fruit in a 6-or 8-quart saucepot. Add lemon juice. Stir in powdered pectin. Bring to a full boil over high heat, stirring constantly. iStir in sugar and spices immediately. Stir and bring to a full rolling boil (a boil that cannot be stirred down). Then boil hard 1 minute, stirring constantly. Remove from heat. Skim off foam with a large metal spoon. Stir jam about 5 minutes to cool slightly and prevent floating fruit. Ladle into jars, leaving about 1/2-inch space at top.With a damp cloth, wipe jar rims and threads clean. Cover with lids and let stand at room temperature 24 hours. Store jam in freezer. (Small amounts can be kept in the refrigerator for up to 6 weeks.) POIRES BELLE HELENE (4 servings) 4 medium-sized pears 2/3 cup sugar 1 1/2 cups water 1 teaspoon lemon juice 1/4 vanilla bean, split, or 2 teaspoons vanilla extract Vanilla ice cream Dark Chocolate Sauce: 2 squares (2 ounces) unsweetened chocolate 6 tablespoons water 1/2 cup sugar Dash salt 3 tablespoons butter or margarine 1/2 teaspoon vanilla

Mix sugar, water, lemon juice and vanilla. Bring to boil and simmer 5 minutes. Meanwhile, peel, halve and core pears. Add pear halves to syrup; poach uncovered 10 to 15 minutes, basting occasionally, until just tender. Do not overcook. Cool pears in syrup.

Make sauce as follows: Combine chocolate and water in saucepan and stir over very low heat until chocolate melts. Add sugar, salt and butter, and stir until mixture thickens and sugar dissolves. Remove from heat and add vanilla. Serve warm. Can be reheated over hot water.

To assembly dessert, put a large scoop of vanilla ice cream in each of 4 bowls. Place two drained pear halves on top, and pour warm chocolate sauce over all. Serve immediately.