They considered an all-garlic dinner, but couldn't think of any suitable desserts. They'd already done two all-chocolate dinners -- complete with chocolate chili and turkey mole -- so that was out of the question. A toothpick dinner and a rotating dinner -- where guests rotate tables between each course -- were two themes that had been done before, too. It was time for Gourmet Group president Dick Taeuber and party organizer Jan Statler to take another tack.

So when approximately 20 members of the singles organization gathered at the Ashby apartment party room in McLean last Sunday, there were yellow tablecloths, at least two guests dressed in lemon yellow, and lemon juice, rinds, slices and halves appearing in a whole range of dishes. This evening's theme was an all-lemon potluck dinner.

"It's not obnoxious," commented single cook Diane Dunhoff, on the food theme of the evening.

With the only restriction being that the final dish was not to be store bought, lemons were used as a garnish, a flavoring, as a main ingredient or as a minor one.

For appetizers, there were lemon butter for artichokes, lemon bagel chips for a caviar dip, lemony baba ghanoush and a spinach lemon dip. The buffet table of main courses spanned the citrus spectrum, from lemon salad dressing to lemon mushrooms to herbed lemon green beans.

In fact, a lemon chicken casserole exemplified the theme so literally that it contained large chunks of camouflaged lemon rind, surprising at least one guest. "I just ate the most unusual vegetable," commented one woman, after chewing laboriously on the rind.

For dessert, there were lemon torte, lemon cookies, a white pepper lemon ginger cake and two lemon mousses. In perhaps what was the most colorful presentation of the evening, Lyle Moore stuffed lemon halves with lemon mousse, spiking the mousse with blue curacao liqueur so that the final dessert was "lizard green," according to its single cook.

Moore said he used lemon cake mix and lemon icing in the recipe, and then melted it down the day of the party and added whipping cream because he didn't like the consistency. "Violently lemon," was how Moore reviewed his resulting concoction.

The problem of matching wine with an all-lemon dinner was tackled by single noncook Dave Langford. Langford went to a liquor store and told the clerk he was attending a rather lemony dinner; the recommendations included two chardonnays, a white zinfandel and a four-liter bottle of Inglenook that Langford left in the freezer to chill a bit too long. It froze and cracked.

As for other beverages, there were bitter lemon soda ("everything else is lemon lime," said Taeuber; "if you're doing a lemon theme, you can't mix in lime"), and two types of lemon tea. But no lemonade. No lemonade? "An oversight," said Moore.

Did any single cooks use store-bought artificial lemon juice? Yes, admitted Joan, who didn't want her last name mentioned. "Don't admit that," urged Moore, sitting next to Joan on the couch full of singleld,10.1 cooks. "Did I do something illegal?" Joan asked.

That got Marge to talking about the friend of hers who worked at a fish shop and washed her hands with lemon juice to get rid of the fishy stench. The friend had separated from her husband of 18 years. "Because she used artificial lemon juice?" chided Hamed.

The temptation for puns was subdued. There were few mentions of sourpusses, sour notes or puckered lips, until guest Bill Spriggs told of his plans to bring a lemon meringue pie, but "it turned out to be a real lemon." Spriggs, who initially identified himself as Bill Lemon, said that the filling was like soup, with the meringue floating on top.

Despite the fact that he couldn't make a successful lemon meringue pie, Spriggs had the nerve to admit that he worked at a bakery as a kid. But, he said in defense, "the bakery went out of business."

Here are some of the lemony dishes the single cooks cooked up for the all-lemon dinner:

BABA GHANOUSH (Makes about 2 1/2 cups)

2 pounds eggplant (2 medium or 1 large)

1/4 cup tahini (sesame paste)

1/2 cup fresh lemon juice

1/2 teaspoon grated lemon rind or more to taste

1 large clove garlic, crushed

1/4 cup finely minced onion

Salt, if desired, to taste

Freshly ground black pepper to taste

1 tablespoon oil, preferably olive (optional)

2 tablespoons minced fresh parsley

Lemon slices for garnish

Prick the eggplant in several places with a fork, place it on a baking sheet, and broil it in a preheated broiler for about 20 minutes, turning the vegetable several times so that the skin chars on all sides. Let the eggplant cool.

When the eggplant is cool enough to handle, cut it in half, scrape the flesh into a bowl, discard the skin, and mash the eggplant with the tahini, lemon juice, lemon rind, garlic, onion, salt and pepper. Cover the mixture and refrigerate it.

Before serving, sprinkle the spread with oil, if desired, and minced parsley, and serve it with pita, fresh or toasted, or as a dip for fresh vegetables. Garnish with lemon slices.

Adapted from "Jane Brody's Good Food Book," by Jane Brody (Norton, $19.95)

MIKE'S CEVICHE (8 to 10 servings)

1 1/2 pounds bay scallops

1/2 cup lemon juice

1/2 cup lime juice

8 scallions, chopped

1 tablespoon minced jalapen o peppers or more to taste

2 tablespoons minced green bell pepper

3 garlic cloves, minced

1 teaspoon each cumin and oregano

Salt and pepper to taste

Place scallops in a bowl. Cover with lemon and lime juice. Add remaining ingredients, stir and cover. Refrigerate overnight and serve.

SHLOMO'S MUSHROOMS IN LEMON CREAM SAUCE (6 servings)

1 cup sour cream

1/4 cup milk

Juice of 1 large lemon

Black pepper and salt to taste

1 tablespoon chopped fresh dill

1 tablespoon chopped fresh parsley

1 pound fresh mushrooms, sliced thinly

Combine sour cream, milk, lemon juice, pepper, salt, dill and parsley in a bowl and mix until well combined. Pour over sliced mushrooms and allow to marinate for 2 to 3 hours in the refrigerator before serving.

WHITE PEPPER AND GINGER LEMON CAKE (8 to 10 servings)

Bread crumbs for dusting

Finely grated rind of 2 large lemons

2 tablespoons lemon juice

1/2 ounce (a piece about 1/2 inch long and 1 inch wide) fresh ginger

3 cups sifted all-purpose flour

3/4 teaspoon baking soda

3/4 teaspoon baking powder

1/2 teaspoon salt

2 teaspoons moderately packed, finely ground white pepper (preferably freshly ground)

2 sticks (1 cup) unsalted butter plus extra for pans

1 3/4 cups sugar

3 eggs

1 cup buttermilk

FOR THE LEMON GLAZE:

1/3 cup lemon juice

1/2 cup sugar

Butter a 10- to 12-cup tube pan (butter the pan even if it has a nonstick finish), dust it with fine dry bread crumbs (be sure to butter and crumb the center tube -- sprinkle the crumbs on the tube with your fingers), then invert it over paper, tap to shake out excess crumbs, and set aside.

In a small cup, mix the rind and juice. Grate the fresh ginger and add it to the lemon juice mixture. Sift together the flour, baking soda, baking powder, salt and pepper and set aside.

In the large bowl of an electric mixer beat the butter until soft. Add the sugar and beat for about a minute. Then add the eggs one at a time, beating until incorporated after each addition.

On low speed add the sifted dry ingredients in 3 additions alternately with the buttermilk in 2 additions. Remove from the mixer and stir in the lemon and ginger mixture.

Turn into the prepared pan. Smooth the top by briskly rotating the pan first in one direction, then the other (the batter will be rather heavy).

Place cake on a rack one-third up from the bottom of the oven and bake for 1 hour and 15 to 20 minutes at 325 degrees until a cake tester inserted gently in the center comes out clean and dry. (If you have used a 12-cup pan the cake will not rise to the top of the pan -- it is all right.)

Let the cake stand in the pan for 5 to 10 minutes. Cover with a rack, turn the pan and rack over, remove the pan, and place the cake on the rack over a large piece of aluminum foil (to catch drippings of the glaze).

Prepare the glaze as soon as the cake is put in the oven. Stir the juice and sugar together and let stand while the cake is baking.

When the cake is removed from the pan, stir the glaze and, with a pastry brush, brush it all over the cake (including the hole in the middle). The cake will easily absorb it all. If some of the glaze drips onto the foil, transfer the rack and pour the glaze that dripped back over the cake.

Let stand until cool.

With 2 wide metal spatulas, or using a flat-sided cookie sheet as a spatula, transfer to a serving plate. This is even better if it ages for a day or two -- the spicy hotness cools a bit as it ages -- covered with plastic wrap. Serve in thin slices.

From "Maida Heatter's Book of Great American Desserts," by Maida Heatter (Alfred A. Knopf, $25) LEMON TORTE (10 to 12 servings)

FOR THE CRUST:

6 tablespoons melted butter

5 1/2 ounces lemon cookies, crushed

FOR THE FILLING:

4 eggs, separated

1 cup sugar

1/2 cup fresh lemon juice

1 1/2 tablespoons finely grated lemon peel

1 1/2 cups whipping cream, whipped

Combine butter and crumbs and press into a 9-inch spring-form pan. Refrigerate.

To make filling, beat egg whites on medium until very foamy. Gradually add sugar, beating constantly until stiff peaks form, about 5 minutes. Beat egg yolks in another bowl until thick and lemon colored. Stir in lemon juice and peel. Gently fold egg whites into yolks, blending well. Gently fold in whipped cream. Pour mixture into chilled crust and freeze. Let stand 15 minutes at room temperature before serving.

From "Laurel Highlands Cuisine" (Latrob Area Hospital Aid Society, $6)