Dinner on a working day need no longer be dreaded by the cook. So much can be bought ready-prepared, from the hors d'oeuvres to the chocolate truffles to be served with coffee. Quality varies, but some products are astonishingly good, better than can be made at home without considerable time and skill. Bearing in mind these tempting (if expensive) additions, I've constructed a minimalist menu, leaving you to have fun buying some extra frills.

First course is shrimp (if you can, buy them fresh and cook them yourself) served with a green herb sauce. Related to Italian pesto but more piquant, the sauce is flavored with parsley, capers and anchovy. This same green sauce is also excellent with oysters on the half shell or cold, steamed mussels.

To stretch the shrimp, you might add, at moderate cost, some halved hard-cooked eggs or a selection of Italian crudite's including bell peppers, zucchini and broccoli. Or, turning totally to vegetables, try green herb sauce with artichokes. Don't forget the bread, for this sauce cries out for a crisp, Italian-style loaf.

The main course is a simple steak, your favorite cut of course, which is pan fried to the point you like it in a heavy skillet with the minimum of fat.

For the sauce, shallots, garlic and herbs are added and the cooking juices are deglazed with red wine (the rest of the bottle is destined for the table).

If, like so many, your tastes turn to white meat rather than red, the same recipe can be used for veal chops. Simply pan fry the chops and deglaze with white rather than red wine, adding a spoon or two of cream if you wish.

Do not, however, overdo the cream; the accompaniment to the meat is a gratin of turnips cooked in creamy tomato bechamel sauce and topped with cheese. I've made this recipe with a variety of root vegetables and, rather unexpectedly, I find this combination to be one of the best. Now I'm waiting until fennel is in season to try it, too.

Trust Julia Child, that master of simple cuisine, to have thought up dessert. Ice cream is a fixture on her table and here she dresses it with a tot of rum and a sprinkling of powdered coffee. Taking her idea as inspiration, I've gone on to suggest such ice-cream combinations as peach ice cream with bourbon and fresh mint and, most luxurious of all, champagne sherbet with raspberries and champagne. Add to this some crisp cookies, your own or from the corner store, and dinner has it made. What to Drink Bearing in mind the minimalist approach of this menu, one wine must suffice both for cooking and drinking. This leads to a light red, something that will not clash with the shrimp and herb sauce yet that has sufficient body to hold its own with the steak. How about a fleurie or a moulin-a -vent or a brouilly, all from the Beaujolais area, but with a bit more body than a plain regional beaujolais. A gamay beaujolais is the domestic equivalent. Dessert comes with its own spirits, or you can choose the champagne sherbet and enjoy a bubbling glass on the side. Timetable

Designed for cooks on the run, this menu has two dishes that can be made ahead, leaving less than an hour's preparation before the party.

Up to three days ahead: Make green sauce and refrigerate.

Day before serving: Boil shrimp if not already cooked and keep in refrigerator. Make turnip gratin and keep in refrigerator.

Forty-five minutes before serving: Peel shrimp and arrange on platter or in stemmed glasses. Whisk green sauce, transfer to serving bowl, and leave at room temperature. Assemble ingredients for cooking steak. Assemble ingredients for ice cream goblet. Set the table.

Thirty minutes before serving: Reheat gratin in oven.

Ten minutes before serving: Cook steaks, cover loosely with foil, and leave in a warm place. Keep pan for deglazing.

After serving shrimp: Deglaze pan and make sauce for steak. Transfer steaks to platter or plates, add sauce, decorate with watercress and serve.

After serving steaks: Assemble ice-cream goblets. SHRIMP WITH GREEN SAUCE (6 servings)

Made with basil instead of parsley, this sauce becomes an interesting, piquant version of pesto.

2 pounds large shrimp, raw or cooked

1 onion, sliced

1 carrot, sliced

1 bouquet garni (2 sprigs thyme, 1 bay leaf, 12 parsley sprigs)

1 tablespoon peppercorns

1/2 teaspoon cayenne

FOR THE GREEN SAUCE:

2 slices white bread, crusts removed

1/2 cup red wine vinegar

Large bunch (1 1/2 ounces) parsley, finely chopped

3 tablespoons capers, drained and rinsed

4 cloves garlic, crushed

4 anchovy fillets

2/3 cup olive oil

Salt and pepper

For the sauce: In a small bowl soak bread in vinegar 10 minutes, then squeeze bread dry. In blender or food processor, pure'e bread with parsley, capers, garlic and anchovy. Note: If using blender, add a little olive oil. With machine motor running, gradually add olive oil. Taste for seasoning. Green sauce keeps 3 days in the refrigerator; it will separate slightly and should be whisked before serving at room temperature.

If shrimp is raw, cook (below). Cooked shrimp can be refrigerated up to 24 hours. Peel them shortly before serving; pass sauce separately.

To boil: For every 2 pounds of shrimp heat 2 quarts water and add 1 sliced onion, 1 sliced carrot, 1 large bouquet garni , 1 tablespoon peppercorns and 1/2 teaspoon cayenne. Simmer 5 minutes, add shrimp and cook just until they lose their transparency, 3 to 5 minutes, depending on size. Drain them; let cool. STEAK MARCHAND DE VIN (6 servings)

1 tablespoon oil

6 club, delmonico, T-bone, filet or other individual steaks

Salt and pepper

4 shallots, finely chopped

2 cloves garlic, crushed

1 cup red wine

6 tablespoons butter, cut in pieces

2 tablespoon chopped fresh parsley

1 tablespoon chopped fresh mixed herbs (chives, tarragon, thyme)

Bunch watercress for garnish

In 2 large skillets heat oil. Sprinkle steaks with salt and pepper on both sides. Set steaks in hot pans and fry briskly until brown on one side, 2 to 3 minutes. Turn over, lower heat slightly and continue cooking until done rare or medium to your taste, 3 to 6 minutes depending on size of steak. Press steak with your finger (don't worry about burns -- there's no danger) to test cooking. The firmer the steak the more cooked it is. Try the edge, then the middle and you'll soon feel the difference. Transfer steaks to a platter. If loosely covered with foil, they can be kept up to 15 minutes in a warm place.

For sauce: add shallots to pan and cook gently until soft, 1 to 2 minutes. Add garlic and cook 30 seconds. Add wine and boil, stirring to dissolve pan juices. Continue boiling until reduced to about 1/2 cup. Whisk in butter over low heat, a few pieces at a time, just until melted. Stir in parsley and herbs and taste for seasoning.

Arrange steaks on platter or individual plates, spoon sauce over, garnish with watercress, serve at once. GRATIN OF TURNIPS, AURORE SAUCE (6 servings)

2 pounds turnips

Butter for baking dish

1 pound tomatoes

1/4 cup grated gruye re cheese

FOR THE SAUCE:

2 cups milk

1 cup cream

2 slices onion

1 bay leaf

10 peppercorns

1/4 cup butter

1/4 cup flour

2 tablespoons tomato paste

Salt and pepper

Pinch of nutmeg

For the sauce: In a pan combine the milk, cream, onion, bay leaf and peppercorns. Bring to a boil, then set aside to infuse 5 to 10 minutes. Melt butter in a heavy pan. Add flour and cook, stirring constantly, until it foams, about 1 minute. Whisk in hot milk mixture, and bring to the boil, stirring constantly. Simmer 2 to 3 minutes, add tomato paste, taste and add salt, pepper and nutmeg to taste.

Peel turnips; cut into 1/2-inch slices. Put in pan of cold salted water and bring to a boil. Cook until tender, 15 to 20 minutes; drain thoroughly.

Butter a shallow 1-quart baking dish. Cut the tomatoes into 1/2-inch slices and spread them in the dish. Put turnips on top, spoon over sauce and sprinkle with grated cheese. Gratin can be prepared up to 24 hours ahead and refrigerated.

Bake gratin in a 375-degree oven until bubbling and top is browned, 15 to 20 minutes if gratin is warm, or 25 to 30 minutes if reheating. Serve gratin in the baking dish.

Tip: Try celery root or fennel instead of turnips in this recipe. JULIA CHILD'S JAMAICAN ICE CREAM GOBLET (6 servings)

Several variations of Child's rum-and-coffee theme are suggested below, as a creative incentive.

1 quart vanilla ice cream

2 tablespoons powdered coffee

6 tablespoons dark rum

At the last minute, scoop ice cream into stemmed goblets. Pour over rum, sprinkle with powdered coffee and serve.

Tip: If coffee is the granular, freeze-dried type, pulverize it in a blender. ITALIAN ICE CREAM GOBLET

1 to 2 tablespoons amaretto liqueur

Peach ice cream

1 tablespoon browned slivered almonds

Pour amaretto liqueur over peach ice cream and sprinkle with almonds. KENTUCKY ICE CREAM GOBLET

1 bunch mint

Bourbon whiskey (2 tablespoons per serving)

Vanilla ice cream

Coarsely chop leaves from 1 bunch mint, reserving one sprig per person for decoration. Pour bourbon whiskey over mint leaves, allowing 2 tablespoons whiskey per person, cover tightly and leave to macerate 2 hours. Scoop vanilla ice cream into goblets, spoon over mint and whiskey and top each goblet with a mint sprig. CHAMPAGNE SHERBET GOBLET (6 servings)

1 pint raspberries or halved strawberries

2 teaspoons sugar

1 tablespoon brandy or kirsch

Champagne sherbet

1/2 glass champagne (per serving)

Sprinkle raspberries or strawberries with sugar and brandy or kirsch; macerate 2 hours. To finish: scoop champagne sherbet into goblets, add macerated fruit and pour over a generous half glass of champagne.