REGIONAL COOKING, we're told, is all the rage in France.What's more, peripatetic Galic chefs cross the Atlantic, carrying their interest in local specialties with them. Once through U.S. Customs, they are ready to start smacking their lips over le Texas barbecue, les crabcakes Maryland and New England Pomme Bette.

However, no one has reported if any of these culinary tourists has yet encountered -- courtesy of Louisville, Ky. -- a simple Benedictine sandwich.

It isn't, I hasten to add, what you might imagine. It is not a squishy mess with a dollop of liqueur oozing between two pieces of bread. Anxious monks can breathe a sigh of relief; any passing Frenchman can taste it without imperiling the national honor.

Rather, Benedictine is a cucumber and cream cheese spread, so named because it was first served around the turn of the century by a Louisville caterer, Jennie Carter Benedict.

A businesswoman and civic leader, Jennie Benedict operated a popular restaurant in downtown Louisville. Author of "The Blue Ribbon Cookbook," she brought her special touch to weddings, tea parties, Derby luncheons and other occasions during the years 1893 to 1925. Though Benedict's has long been gone from Louisville's Fourth Street, Miss Jennie's tasty cheese concoction is still being made and eaten in the area.

Two competing brands of Benedictine are produced commercially and sold not only in Kentucky but in southern Indiana and southern Illinois, as well. When I was growing up in Louisville, a green-and-white striped carton with the label Land O' Grass was a familiar sight in my mother's icebox. This brand of Benedictine was luridly tinted with green food coloring -- all year round and not just on St. Patrick's Day. It took me a while to learn to appreciate a paler, homemade version.

Benedictine is delicious as a tea sandwich on thinly sliced bread with the crusts cut off. I serve it in a bowl, surrounded by cocktail rounds of pumpernickel. One can also use it as a dip for crudites or chips. Here are the ingredients: BENEDICTINE 8-ounce package cream cheese Mayonnaise (or milk) Grated pulp of 1 small cucumber, peeled and seeded 1tablespoon grated onion 1 teaspoon salt Few grains cayenne (or dash hot pepper sauce)

Mash the cheese with a fork or heavy wooden spoon, thinning the consistency a bit with either mayonnaise or milk. Work in the grated pulp, after wringing it dry on a napkin or paper towel. Blend in the onion cautiously, tasting to make sure that the flavor enhances and does not overpower the delicate cucumber taste. Add salt and cayenne or hot pepper sauce. Keep stirring until a good texture -- for either spreading or dipping -- is obtained. A few drops of green coloring is traditional; outside of Louisville it's optional. Chill until ready to serve.

While Louisville may not be the birthplace of the cheeseburger (as Kaelin's, a fixture among family restaurants there, suggests on its menu), it is undisputably the home of the "Hot Brown." That, along with its warm-weather mate, the "Cold Brown," is the logical next step to master in Kentucky sandwich arcana, after Benedictine.

Taking its name from the hotel in whose kitchen it originated, the Hot Brown has become part of Louisville city lore.The Brown Hotel opened in 1923, and it seems likely that the Hot Brown was first served to diners not long after. Uncertainty also attaches itself to the correct spelling of the name of the president chef at the time: Was it Laurent Gennari or Lorentz Genare? (It would have been helpful to his culinary immortality had he called his popular sandwich after himself and not after his employer.) The Brown, now closed, was the favorite child of an eccentric Louisville tycoon, J. Graham Brown. It was famed for its Bluegrass Room, and its demise was mourned by the community.

However, many restaurants in the Louisville area still serve one or another kind of Brown sandwich. Here are recipes for both the hot and cold versions; either is fine for lunch or a light supper. HOT BROWN (4 open-faced sandwiches) 2 tablespoons butter or margarine 1tablespoon flour 1 cup light cream or milk 3/4 cup mild cheddar cheese, grated Pinch of grated nutmeg Dash of cayenne pepper 1 teaspoon salt 1/8 teaspoon pepper 4 slices toasted white bread 4 slices cooked white meat of chicken or turkey 8 slices crisp bacon, drained 1/4 cup parmesan cheese, grated

Melt butter and stir in flour, cooking 2 or 3 minutes without letting it brown. Add the cream or milk slowly, cooking until thickened and smooth. Stir in cheddar cheese, nutmeg, cayenne, salt and pepper. Heat over low fire until cheese is melted.

Set the pieces of toast in a shallow baking dish, putting a piece of meat on each slice. Cover evenly with the cheese sauce.Arrange two slices of bacon on each sandwich, then sprinkle with the parmesan. Put under preheated broiler until the parmesan melts and turns a golden brown.

Serve immediately. COLD BROWN (4 open-faced sandwiches) 4 thin slices rye bread, crusts removed Butter for bread (optional) Bibb or leaf lettuce 4 slices white meat of chicken or turkey 4 slices ripe tomato, peeled 4 hard-cooked eggs, slices in rings Thousand Island dressing to top

For this open-faced sandwich, the bread may be lightly buttered, if you wish.

Place first the lettuce, then the meat, then the tomato, then the egg pieces on the bread. Garnish with more lettuce leaves and then cover with the dressing. It is to be eaten, of course, with a knife and fork. Says Marion Flexner, from whose "Out of Kentucky Kitchens" this recipe is adapted, "In summer we serve this with iced tea in which a scoop of lime or lemon sherbet has been placed.