THREE TIMES a week Cindy Cooper walks over from her office to the Bethesda Avenue Coop where she decides what she will cook for dinner that night. She never plans ahead. She chooses a menu based on what looks best and is most reasonable that day.

On weekends she cooks up a 10-quart pot of kidney beans or garbanzos and freezes them in small packages, each enough for one dinner for herself and her husband, Pat Patterson.

Some dishes are made in double quantity, enough for two meals: tomato sauce for chili or manicotti, green beans, served hot the first night, in a vinaigrette one or two nights later; baked potatoes one night which become panfried the next.

"One of the biggest helps is making twice as much as you need. It's no more trouble," says Cooper, who works as a research assistant for Biostatistics Center.

And that's how one working couple copes with a vegetarian diet without resorting to more than an occasional carryout or convenience food meal. Restaurants are a once-a-week luxury.

Once in awhile they have a pizza and when they are really too tired to cook they have frozen prepared stuffed pasta shells or spinach souffle. But Cooper would rather not do it. "They have to have a lot of preservatives and things I don't really like every day," she said. "But it's a tossup between that and going some place cheap and getting things and not knowing what's in them."

Cindy and Pat are the model young working couple: The two nights a week when she goes to school she cooks. But they never cook together. "We leave each other alone in the kitchen. We not only bump into each other physically [it's a very small kitchen], we bump into each other mentally," says Patterson, assistant director of legislative affairs for Menswear Retailers of America. "I'll dirty everything and love it and not mind cleaning up after it and Cindy won't mess anything at all."

They share all the housework. Cooper says she does a few more things in the house, but Patterson takes care of the car. When she cooks, he washes the dishes.

Who does the laundry?

Whoever wants theirs first!"

Cooper was a vegetarian before she married Patterson. She converted him without much difficulty despite the fact that he considers himself a meat and potatoes man. His mother, he said, couldn't get him to eat vegetables. "At first I felt hungry. I ate a lot of starch and gained a lot of weight."

Eventually it got easier, but Cooper says that becoming vegetarian "is really an effort at first. To eat nutritiously takes a couple of months and then it becomes a habit. You really think about it a lot more if you don't eat meat."

On occasion Cooper will eat fish, "but not by choice unless it will embarrass someone." This thoughtfulness does not extend to chicken or red meat. Patterson, less committed, eats fish more willingly. "And when I go by a barbecue place and smell it. . .oh hold me back!"

Cooper is equally drawn to the aromas of cooking meat. "That's the funny thing -- the olfactory part -- it still smells good." m

By this time someone may be thinking that the only person who can be a vegetarian is one who doesn't like to eat. The assumption is wrong. Both Cooper and Patterson love food, he perhaps even more than she.

"It's in my blood," says the tall, blond native Washingtonian, referring to his mother, Shang Patterson, who has the reputation as one of the city's finest cooks.

He loves to cook and experiment as much as his mother. "I can never make the same thing twice. If I don't have something in the house when I'm in the middle of cooking I'll run up to the store and get it."

His wife says his tastes are more exotic than hers. "He sees cooking as a challenge. Pat's palate needs lots of stimulation. He likes unique tastes, spicy food." So there are lots of Indian, Mexican and Chinese dishes in their repertoire.

The nights Cooper is not at school, where she is working toward an advanced degree in art history, she gets home at 5. It takes her about an hour to prepare dinner. "I'll spend a lot of time on the main dish, but for a side dish we usually have a salad. To keep it from getting boring we have a lot of different dressings [all homemade]."

More often than not there is a dessert.

Both Cooper and Patterson confess to certain junk food addictions. She loves potato chips. "Probably I go for the salt because I know I shouldn't eat it."

Patterson loves ice cream and key lime pies. Cooper's parents have a key lime tree in their yard in Key West and send several care packages during lime season. When they arrive Patterson goes on his key lime pie binge. "I'll make them consecutively until I use up all the limes," he said. "After I make one I eat it one hour after another until by the evening half is gone. By the end of the second day it's all gone. I make the second pie on the third day, etc."

Both of them exercise extensively. He jogs 25 to 30 miles a week and works out with weights; she jogs about 9 miles a week and does stretching exercises.

It makes binging on potato chips and key lime pies possible. CHEESEY SQUASH (4 servings) 2 medium yellow squash 2 medium zucchini 3 tablespoons olive oil 3 cloves garlic, chopped 1 large sliced onion 2 stalks sliced celery 1 teaspoon each oregano, basil, thyme, majoram Grated black pepper Salt to taste 1/2 cup seasoned bread crumbs 2 cups grated sharp cheese Paprika Butter

Scrub squashes and cut in 1/2-inch slices. Combine with oil, garlic, onion, celery, herbs, salt and pepper. Steam for about 20 minutes, until vegetables are crisp tender. Place in oblong baking dish; top with bread crumbs and cheese. Dot with butter and sprinkle with paprika. Bake at 350 degrees for 15 minutes or until brown. FRIED TOFU (Four 1/2-inch slices) 1/2 pound hard tofu, drained, cut in 1/2-inch slices 1 egg, beaten 1/2 cup flour 1/4 teaspoon garlic powder 1/8 teaspoon ground ginger 1/4 teaspoon salt 3 tablespoons sunflower oil

Press tofu between paper towels to remove excess moisture. Dip slices in beaten egg. Mix dry ingredients. Dredge slices in dry ingredients. Pan fry in oil until golden on both sides. GREEN BEAN SALAD 2 cups cooked crisp fresh green beans 1 tomato, peeled and seeded 1 scallion, sliced Juice of 1/2 lemon 1 tablespoon olive oil Sprinkle of dill, salt, black pepper

Combine all ingredients; mix. This tastes best if left all day or overnight in refrigerator. Manicotti (3 to 4 servings) Crepes: 2 eggs 1/4 cup milk 1/4 cup water 1/4 teaspoon salt 1 tablespoon melted butter 1/2 cup flour

Mix all ingredients in bowl except flour. Beat with electric mixer then add flour and beat to mix well. Make 9 crepes and let them cool. Filling: 1 egg 1/2 pound ricotta cheese 3 ounces grated mozzarella cheese Salt and papper to taste 1 1/2 teaspoon chopped parsley 1/4 cup grated Parmesan cheese Tomato Sauce (see recipe)

Blend all ingredients but Parmesan and tomato sauce. Place two tablespoons of filling on each crepe and fold ends over. Place in baking dish, folded side down. Cover with about 3 cups tomato sauce; top with Parmesan. Bake at 400 degrees for 20 minutes. VERY QUICK TOMATO SAUCE (About 9 cups) 2 large onions, chopped 5 large cloves garlic, chopped 4 tablespoons olive oil 2 teaspoons each basil, oregano, thyme 3 (1-pound) can whole tomatoes 1 1/2 teaspoons salt 1 1/2 teaspoons sugar 2 cups sliced mushrooms 1 (6-ounce) can tomato paste

Simmer onions, garlic, oil, herbs until onions are transparent. Place tomatoes in blender with simmered ingredients; puree. Return to saucepan with remaining ingredients; simmer about 20 minutes. Serve and store remainder in freezer in portions suitable for family's use. STIR FRY VEGETABLES (2 servings) 2 stalks celery 1 carrot 3 spring onions 1/2 can sliced water chestnuts 1/2 red or green pepper 8 large mushrooms 2 tablespoons oil 2 cloves garlic, crushed 1/4 cup soy sauce 1/4 cup hoisin

Slice all vegetables at 45 degree angle. Heat oil and garlic in a heavy pan or wok. Add vegetables and stir fry for 5 minutes. Add soy and cook 2 minutes longer. Before serving mix in prepared hoisin or sweet and sour sauce. BLEU CHEESE DRESSING (4 servings) 1 cup plain yogurt 3 tablespoons mayonnaise 2 ounces crumbled bleu cheese Freshly ground pepper Salt to taste

Combine ingredients. Best served the next day.