Dinner for one: an elegant meal which is fun to prepare

''A is for dining Alone,'' wrote M.F.K. Fisher in ''An Alphabet for Gourmets, '' ''and so am I, if a choice must be made between most people I know and myself.''

Whether or not one agrees with her admittedly misanthropic attitude, dining alone need not be lonely. The menu below offers some suggestions for one who, for whatever reasons, chooses to enjoy the pleasures of the table alone.

Artichoke, that prickly flower from the thistle family, makes a beautiful and convenient first course. After cooking it the hour or day before, remove the inner leaves and choke, then fill the cavity with lemony mayonnaise. Dip each leaf into the sauce, and finally savor the heart hidden beneath.

Most Americans ignore the vegetable fennel. Similar to celery in appearance but possessing its unique anise flavor, fennel combines well with many foods including fish.

In this recipe it is simmered, topped with Parmesan, then baked in the same dish with a salmon steak. The complementary flavors set each other off as admirably as the pale green and salmon colors.

With its substantial first course this dinner needs no salad, but have a lettuce or tomato vinaigrette if you like.

Dessert is a pear half caramelized briefly under the broiler, then sprinkled with toasted almonds and garnished with whipped cream. It makes a disarmingly simple and satisfying combination of tastes and textures. Artichoke With Lemon Mayonnaise 1 medium artichoke Lemon wedge 1 thin slice of lemon for garnish

Wash artichoke thoroughly under cold running water. Break off stem and pull away rough leaves around it. With sharp knife trim bottom to stand straight and look smooth; cut off top inch of crown.

With scissors snip off tops of outside leaves. To keep flesh from turning dark, rub with a piece of cut lemon.

Place artichoke in a pot of boiling salted water then cover with a heatproof dish to keep it submerged. Boil about 40 minutes, uncovered. Artichoke is tender when a leaf comes out easily. Place in cold water to cool, then drain upside down until completely dry.

If you cook the artichoke a day ahead, refrigerate, but allow to return to room temperature before serving. Pull out inner leaves and hairy choke and spoon lemon mayonnaise into cavity. Garnish top with lemon. Lemon Mayonnaise 1/4 cup mayonnaise 1 tablespoon grated lemon zest 1 tablespoon lemon juice 1 teaspoon mustard Salt and freshly grated pepper to taste

Combine seasonings with mayonnaise and mix well. When you grate lemon zest, be sure to use only the outer yellow part, not the bitter inside of the rind. Salmon and Fennel au Gratin 1 fennel bulb Butter 2 to 3 tablespoons freshly grated Parmesan or Romano cheese 1 salmon steak about 1 inch thick 1 tablespoon chopped fennel leaves 1 1/2 tablespoons butter cut into small pieces Salt and pepper to taste

Wash and trim fennel bulb. Cut stalks into 1-inch lengths and quarter bulb. Drop pieces into pot of boiling salted water, return to boil, and simmer for 15 minutes, until tender. Drain well. Butter shallow baking dish of medium size and arrange fennel around outside. Grate cheese over fennel and place salmon steak in middle.

Chop a tablespoon of feathery fennel leaves and sprinkle them on salmon. Dot fish and fennel with butter and salt and pepper to taste. At this point you may refrigerate dish, covered, overnight. To serve, bake in preheated 350-degree F. oven for 15 minutes until salmon is just cooked through and cheese is beginning to color. Pear With Pound Cake and Almonds 1 pear half, poached or canned 1 teaspoon sugar 1 slice pound cake 1 tablespoon slivered almonds, lightly toasted in oven Whipped cream Confectioners' sugar Grated nutmeg

Put pear half core side down in small shallow baking dish. Generously sprinkle it with sugar, about a teaspoon. Run it under broiler, not too close, to caramelize sugar. Watch carefully to see that sugar does not scorch. Remove it when pear is nicely browned.

Cut a slice of pound cake and put pear on top, core side down. Trim cake to shape of pear. Scatter almonds on pear and spoon whipped cream, sweetened to taste and flavored with nutmeg, around the outside.