SUPERMARKET delicatessens are offering some pretty interesting versions of meat loaf these days. From "pa te'" to "pizza loaf," however, it's just meat loaf by another name.

The meat loaf of our youth gets paired in memory with ketchup or worcestershire and the leftovers always went into sandwiches. As children, we rarely thought of meat loaf as fancy food, but Julia Child makes a fairly strong argument for it in "From Julia Child's Kitchen:"

A combination of fresh ground meats mixed with wine and spices, baked in a comfortable dish and served cold in thick, fragrant slices, makes a marvelous first course and is luxurious on a picnic, or with tossed greens and a bottle of wine. That's the French terrine or pa te'; if you can make a meat loaf, you can make a pa te'. It's as simple as that.

From American meat loaf and French pa te', one naturally becomes whimsical about creating other ethnic variations. Substitute crushed tortillas for bread crumbs in conventional meat loaf. Replace tomato sauce with taco sauce and green pepper with green chilies and, faster than you can say "ole'" meat loaf becomes Mexican.?

It's easy to see that meat loaf by any name is a great trick to learn. For very little effort, you can assemble one and let it season in the refrigerator for a day or two (or not, as time allows). The wait improves a meat loaf as a wait improves a pa te'.

In fact, meat loaf has all the advantages of Julia Child's pa te' . . . serve as a first course sliced thin, or sliced cold and served for dinner with vegetable salads . . . and it, too, becomes a filling for sandwiches to carry off to a picnic or the park. Serve Sicilian Meat Loaf with salad, a good, crusty Italian bread, fresh mozzarella cheese and hearty red wine. Bratwurst naturally calls for chewy, strong bread -- a rough pumpernickel or rye -- mustard and lots of pickles. Peppery Chicken Loaf would do well with chilled white wine and roasted sweet peppers (red and green) with their skins removed and marinated in vinaigrette. The Creole loaf needs a relish of sweet and hot peppers with onions, french bread and cold beer. SICILIAN MEAT LOAF (4 to 6 servings) 1 pound ground beef 1/4 pound highly-seasoned Italian pork sausage 1/2 cup chopped black olives, preferably Greek 1/2 cup chopped pimiento-stuffed green olives 1 teaspoon dried rosemary 1 large onion, minced 1/2 cup red wine 1/2 teaspoon salt 1/4 teaspoon black pepper 1/2 cup beef broth, homemade or canned 1/2 cup bread crumbs 2 large eggs, slightly beaten 1/2 cup minced parsley 1 cup grated romano cheese

Grease a 6-cup loaf pan generously. Combine all ingredients in a large bowl until thoroughly mixed, working with a wooden spoon or kneading with your hands. Turn into the prepared pan and bake for 1 hour at 400 degress. Drain if necessary. Cool in the pan, remove and wrap tightly; refrigerate for 1 day before slicing. For a more intense flavor, prepare the loaf and store the uncooked ingredients in the refrigerator for a day before baking. BRATWURST LOAF (4 to 6 servings) 3/4 pound ground veal 1/2 cup milk 2 cups soft bread crumbs 1 medium onion, chopped 2 large eggs 1/2 pound pork, ground twice 1/2 teaspoon each caraway, thyme and ground nutmeg 3/4 teaspoon salt 1/4 teaspoon pepper

Generously grease a 6-cup loaf pan, line the bottom with waxed paper and grease the paper. In the container of a blender or a food processor, combine veal, milk, bread crumbs, onion and eggs. Blend until the mixture is pure'ed (you may have to do this in 2 batches). In a large bowl, combine the pork, herbs and seasonings. Add the veal pure'e and work the mixture together until well combined. Turn into the prepared loaf pan and bake in a 350-degree oven for 45 minutes, or until top is lightly brown and juices run clear. Cool to room temperature. Remove from the pan, peel off the paper, wrap tightly and store in the refrigerator for at least a day before slicing. Keeps very well. Serve with a selection of mustards or a mixture of sour cream and horseradish. PEPPERY CHICKEN LOAF (6 to 8 servings) 2 or 3 Italian hot sausages, depending on size (see recipe) 1 small onion, diced, plus 1/2 cup chopped onion 1 small green pepper, diced 1/2 medium sweet red pepper, diced 2 tablespoons olive oil 1 ripe tomato, peeled, seeded and diced 1 1/2 pounds raw chicken breast, skinned, boned and cut into 1-inch dice 3/4 cup white wine 1 1/2 cups soft white bread crumbs 2 large eggs 1/2 teaspoon rosemary 1 teaspoon salt 1/2 teaspoon freshly ground black pepper

Butter a 7- to 8-cup loaf pan, line the bottom with waxed paper and butter the paper. You will need enough sausage to span the length of the loaf pan after they are cooked. Place the sausages in a small skillet with 1/2 cup of water and simmer until the water disappears and sausages are lightly brown. Turn them frequently until they are cooked through, and set aside to cool.

Cook diced onion and green and red peppers in olive oil over moderate heat until quite soft, about 10 minutes. Add diced tomato to the saute'ed ingredients and cook until moisture has disappeared. Set aside to cool.

Place diced chicken in a blender or food processor with 1/2 cup of chopped onion, white wine, eggs, bread crumbs, rosemary, salt and pepper. Blend until the ingredients are pure'ed, scraping down the sides of the container and rearranging the solid pieces in the blender from top to bottom until the mixture is an even texture. Place chicken mixture in a bowl and fold in the saute'ed vegetables.

Arrange half of this mixture in prepared loaf pan. After trimming the ends of the sausages, line them down the center end to end, pressing them lightly into the pure'e. Add remaining pure'e and smooth the top. Bake in a 350-degree oven for 40 minutes, or until the top begins to brown. Cool to room temperature, turn the loaf out of the pan and remove waxed paper. When cold, wrap tightly and store in the refrigerator at least a day before cutting. CREOLE MEAT LOAF (4 to 6 servings) 1/4 pound genoa salami 1/2 pound ground pork 1/2 pound ground beef 1/3 cup raw rice cooked in 2/3 cup salted water 1/2 cup each chopped onion, green pepper, roasted red pepper 1 cup tomato sauce 1/2 cup white wine 2 large eggs 1/2 teaspoon salt 1/4 teaspoon black pepper

Grease a 6-cup loaf pan and set aside. With a sharp knife, cut salami in small dice, add ground pork and chop together until salami is quite fine. Or put pork and salami through a meat grinder. Combine with beef in a bowl. In blender container or food processer, place the cooked rice, onion, green pepper and roasted red pepper with tomato sauce, white wine, eggs and seasonings and about 1/4 of the meat mixture. Process to a pure'e, scraping down the container frequently. Pour into the bowl with the meat. Mix together thoroughly, turn into the prepared loaf pan and bake in a 400-degree oven for 1 hour. Remove from the pan when cool, wrap tightly and refrigerate for at least a day to develop flavor.