Tortola, British Virgin Islands — It has all the chic entertainment value of a New Yorker cartoon. Take a sophisticated urban couple - one partner an ex-TV writer and the other a former investigative reporter and Neiman fellow - and place them on a tropical island that has frequent power outages and a local populace who prefer Mexican cuisine.
The result: chocolate mousse cake.
And where there's chocolate mousse cake, can shrimp bisque and pasta with lime cream be far behind? Not if Jeff and Jinx Morgan are in the kitchen of the Sugar Mill Hotel and restaurant here.
The Morgans write the ''Cooking for Two'' column in Bon Appetit magazine and are the authors of ''Two Cooks in One Kitchen'' (Doubleday & Co., 1983).
After several years as travel and food writers, they moved from northern California to the Caribbean and became the latest operators of the Sugar Mill - an inn that had already earned a reputation as ''one of the best kitchens'' in the Caribbean.
The morning I arrived in the open-air dining room, the Morgans talked about the sometimes humorous trials of running a fine restaurant in the middle of the tropics.
''We had never even heard of the British Virgin Islands until we bought the hotel,'' says Mrs. Morgan.
Despite some obstacles, the Morgans have flourished in their new Caribbean milieu. Since arriving at the hotel, they have substantially altered its menu by introducing such dishes as herb-grilled eggplant, grouper salad, and pork with wild mountain thyme to the kitchen's offerings.
''My impetus is always fresh herbs and more than two kinds of lettuce,'' says Mrs. Morgan, who perfects the recipes in her own kitchen before passing them along to the staff.
''We want to show that you can be cooking creatively wherever you are, to use what is available in interesting things. We're not nouvelle cuisine. In fact, if I hear of one more 'warm lamb salad, . . .' '' she threatens.
The couple visit the local market for fresh fish, mangoes, avocados, and soursop, and they have discovered an island bakery that will deliver the bread ''straight from the ovens to our freezer,'' says Mr. Morgan. ''The humidity here is a terrible problem with baked goods.''
As for the rest of their supplies, the Morgans, like every other island eatery, import their meats and staple items on weekly flights from New York via Puerto Rico.
They have also begun a series of week-long cooking classes held during the summer months and appropriately called ''Cooking in Paradise.''
Relatively sophisticated dishes using local ingredients are the emphasis. Students help prepare lobster creole, conch creveche with coconut cream, banana beignets, and breadfruit vichyssoise, all of which are then served as lunch in the Morgans' own kitchen.
Classes will run the first and last weeks in June, July, and October. Fees, not including air fare, are approximately $855 per person double occupancy and include seven nights' lodging, breakfasts, several dinners at the hotel, a picnic, an evening at a West Indian restaurant, and visits to local markets.
For further information write: Cooking in Paradise, Sugar Mill Hotel, PO Box 425, Tortola, British Virgin Islands; or call (809) 495-4355.
Here are some recipes from the Sugar Mill Hotel: Dorado in Creole Sauce 8 pieces dorado (about 4 pounds) or any firm textured white fish, skinned Salt and pepper Lime juice Butter Water Sauce: 1 large onion, chopped 2 cloves garlic, minced 1/4 cup butter 2 red peppers, seeded and cut in thin lengthwise slices 2 green peppers, seeded and cut in thin lengthwise slices 1 small hot pepper, seeded and minced (optional) Salt and pepper 1 cup minced parsley
Rinse fish and pat dry. Sprinkle with salt and pepper and lime juice. Dot with butter. Place in baking dish and pour boiling water over until it reaches halfway up the fish.
Cover and bake in a 350-degree F. oven for 10 minutes for every inch of thickness of the fish. For sauce, saute onion and garlic in butter until limp. Add peppers. Cook until tender but not mushy. Season to taste with salt and pepper. Add chopped parsley just before spooning sauce over fish. Meringue Seashells with Banana Cream 4 egg whites 1 cup sugar 1 cup heavy cream 1 to 3 tablespoons powdered sugar 1/2 teaspoon vanilla 2 bananas, peeled and chopped
Preheat oven to 250 degrees F. Brush a baking sheet with oil and dust with flour.
Beat egg whites until they form stiff peaks. Add 4 teaspoons sugar and continue beating until mixture is glossy. Gradually fold in remaining sugar with a metal spoon.
Fit pastry bag with a 1/2-inch plain tip and fill with meringue mixture. Pipe meringue onto baking sheet to form coiled shell shapes or form mixture into shell shapes using two spoons, to make 16 shells. Sprinkle with additional sugar to give shiny gloss.
Bake about 1 hour. When firm, lift meringues with a sharp knife from sheets and press bottoms gently to form a hollow. Replace on baking sheets, hollow side up and continue baking 20 to 30 minutes or until very dry and crisp. Cool on wire racks.
Whip heavy cream until it begins to stiffen. Gradually add powdered sugar, to taste, and vanilla. Fold in chopped bananas. Fill hollows of meringues with banana cream. Press one filled meringue against another to form a sandwich. Completed meringues will look like tropical seashells.