ONE MORNING Tom Harvey woke up and realized that it was going to be his turn to cook dinner that night, and the next, and the next, and the next . . . Harvey had just separated from his wife. What made matters worse was that Harvey's wife was a graduate from the CIA (Culinary Institute of America), a food writer and a very good cook.

At first, Harvey had a hard time adjusting. But soon he was darting around his kitchen with increasing enthusiasm and competence, as he tried one recipe after another on friends. Then Harvey realized that out there were thousands of former partners who had to adjust to the new shape of their lives and who knew little about cooking and solo entertaining. He decided to do something about it. A course was born -- "Cooking for New Singles."

Harvey was a Wall Street lawyer until 1977, when he came to Washington to be, successively, a White House Fellow, a special assistant to the director of the Central Intelligence Agency, deputy assistant secretary of the Navy for logistics and, as of April 1, not otherwise gainfully employed.

Perhaps because of his legal training, Harvey prepared for his first class thoroughly -- numerous drafts of the written materials and endless experiments in the kitchen. Then, as behooves a lawyer, Harvey went through a set of moot courses earlier this year, enlisting eager and sometimes knowledgeable friends to play the part of students. The panels' questions were not always easy, and once or twice Harvey seemed about to be stumped -- for example, when he was asked if sauteing proceeds more rapidly with salted than unsalted butter. (It does, according to Harvey.)

The course is conducted in the small but well-appointed kitchen in Harvey's McLean condominium. A half-dozen chairs are all that fit into the kitchen, so that is the maximum number of students Harvey can handle and still have room to dice. As the meal is prepared, students sample dishes and volunteer advice or ask questions. At times, Harvey stops to offer a taste of a sauce in progress or to divide a sauce into two parts, adding, say, olive oil to some, peanut oil to the rest, for comparison purposes. The dishes are generally straightforward, but with a hint of elegance, like a cheese souffle or a roast leg of lamb with garlic. A few dishes are simply fun, like chimney sweep ice cream. When preparation is complete, the teacher and students are off to the dining area, where, surrounded by plants and tropical fish, the preparations -- usually an appetizer, main course, salad and dessert -- are consumed.

Central to Harvey's idea of a good cooking class is that everyone have a good time. "I once substituted for my wife at a class of James Beard's in New York. Among the things I remember best is that the students enjoyed themselves while they learned." Along with a dry, witty presentation (which includes an off-color broccoli story), Harvey serves up a more than generous amount of moderately priced and suitable wine, usually two, "so we can compare wines with the same dish." Soon stripped of an inhibition or two, everyone has fun.

Even when one dish had to be thrown out, there was no evident chagrin. Harvey had introduced the chocolate chip cookie course demonstration by stating that he had never had this recipe fail. It failed. The commercial bran cereal he substituted for the custom-made health store variety he usually uses neglected to absorb the liquids. What emerged was the largest and thinnest chocolate chip cookie ever seen in Northern Virginia. The second try was an unqualified success.

Finally, when everything else is set, how does one decide what to charge for his first set of cooking classes?After talking with the people who sat in on the practice classes, Harvey decided to charge what the meals with wine would cost at a medium-priced restaurant -- $80 per person for four sessions, including the right to bring a guest at the fourth. The student trades the restaurant's ambiance and service for Harvey's good-humored instructions -- a good exchange, according to those who attended the practice sessions. Harvey hopes the paying customers will agree. Based on the reaction at his first class last week, it's full speed ahead. LA GOUGERE (Cheese Puffs) (4 to 6 servings) 1 cup water 1/2 cup butter 1/2 teaspoon salt 1/4 teaspoon nutmeg 1/4 teaspoon pepper 1/2 teaspoon red pepper 1 cup flour 6 eggs 2/3 cup grated swiss cheese Small thin slices swiss cheese

Place water, butter and seasoning in saucepan and bring to boil. Add flour all at once. Beat with a wooden spoon until the mixture leaves the sides of the pan and forms a ball. Remove from heat and place in mixing bowl. Beat 4 eggs in, one at a time, adding a fifth egg only after the previous one has been absorbed. After the fifth egg has been added, continue beating until the mixture is smooth and shiny. Stir in the grated cheese.

Sprinkle baking pan with light dusting of flour. Mark a ring of about 9 inches in diameter in the flour. Spoon the mixture in walnut-sized mounds to form 2 concentric circles. Beat together the last egg and a teaspoon of water and brush this mixture over the circles. Completely cover the surface with the slices of cheese. Bake at 425 degrees until puffed, crisp and a golden brown, about 30 minutes. ROAST CHICKEN (4 servings) 4- to 5-pound roasting chicken 1/2 lemon 3 tablespoons unsalted butter, softened 1 teaspoon salt 1/2 teaspoon pepper 1 teaspoon dried tarragon 2 tablespoons chopped parsley 1 onion, peeled and quartered 1 celery stalk with leaves 3 feet of string for trussing

Rinse the chicken and rub its cavity with the 1/2 lemon, squeezing the juice onto the chicken as you do. Cream 2 tablespoons of the butter, salt, pepper, tarragon and parsley and place the mixture into the cavity with the onion and celery stalk.

Truss the chicken. Rub the chicken with the remaining softened butter and place it on a rack in a roasting pan (not directly on the roasting pan) in a 425-degree oven. After 20 minutes, turn the chicken, baste the upper sides with melted butter from the pan and roast 20 minutes longer. Roast an additional 20 minutes on its back, basting the chicken well with the pan juices. Sprinkle with salt and pepper. When the leg and thigh move easily, the bird is done. Puncture near the thigh joint. If the juices run clear, it is definitely done. A meat thermometer inserted in the fleshy part of the thigh (avoiding a bone) should register 165 degrees. A 4-pound chicken should take approximately 1 1/4 hours to roast. Allow the chicken to rest 15 minutes after cooking to absorb juices. FRENCH GREEN BEANS (4 to 6 servings) 1 1/2 pounds fresh green beans 3 quarts salted water 3 tablespoons butter 3 shallots, minced

Rinse the beans, then cut off their stem ends. Boil 3 quarts salted water and, when boiling, add the beans. Boil for 5 minutes and drain. This just cooks the beans, leaving them a bright green color and still crunchy. This can be done well before you are ready to serve the meal.

Just prior to serving, melt the butter in a large skillet. Mince the shallots and add to the butter. Cook the minced shallots about 2 minutes, then add the beans, tossing to warm them, and cover each with the melted butter and shallots. CHIMNEY SWEEP ICE CREAM (6 servings) 2 pints good vanilla ice cream 6 tablespoons scotch whiskey 1 tablespoon finely ground espresso coffee beans

Over scoops of ice cream in individual serving bowls, pour 1 tablespoon scotch. Dust the top with 1/2 teaspoon of the finely ground espresso. It is important to use good ice cream for this dessert. The combination of rich ice cream, scotch and coffee is unusual -- and delightful.