EVERY COOK has one. It's always there, hidden away in cupboards or the refrigerator. It's fast and it's filling, and it's on hand just when you need it the most. What is it? It's the standby recipe. The meal you make when it's a dark and stormy night and you don't want to go to the grocery store in the rain. The meal you put together when you don't want anything fancy, just a satisfying supper. The meal you make when you're too tired to go to the fuss and bother of fixing anything else.

Different cooks have different standby meals, but whatever their recipes, they always make sure that the makings are on hand. Inevitably the ingredients become a part of the staples section of the weekly shopping list. There are a number of Hall of Fame standards in this genre of recipes to fall back on: the most prevalent are omelets, tuna salad, cottage cheese and fruit, hamburgers, even fried-egg sandwiches.

But there are a number of other main dish meals that fit the bill, meaning they're tasty and comforting, and that they're as quick (or almost as quick) as the classic standbys. If you're feeling in a culinary rut they'll be a welcome addition to your quick-cooking repertoire. These are some of my favorite standbys, plus a few from other cooks. MATZO BRIE WITH WALNUTS (2 servings)

This is a variation of the traditional matzo brie, a mixture of matzo fried in eggs and butter. I prefer egg-and-onion matzo, although plain matzo could be used.

3 sheets of matzo

2 eggs

2 tablespoons milk

Seasoned salt

Pepper

2 tablespoons butter

1 heaping tablespoon chopped walnut pieces

Crumble the matzos into 2-inch pieces. Cover with water to soften a bit, then pour off the water right away. Press to extract any excess water. In a separate bowl beat the eggs together with the milk, seasoned salt and pepper. Melt the butter in a medium-sized skillet. Mix the matzo and milk mixture together, and add to the skillet. Stir frequently, add the walnuts, stirring until the mixture begins to turn golden. Add more seasoned salt and pepper to taste. SALMON CAKES WITH MUSTARD SAUCE (2 servings)

7 3/4-ounce can red sockeye salmon

1/4 cup cracker crumbs

1 egg, beaten

1/4 teaspoon salt

1/4 teaspoon dill weed

Butter

Drain and flake the salmon. Mix in the remaining ingredients, except the butter. Form into four patties. Saute' in butter until brown. Serve with a dollop of dijon mustard, or with the mustard sauce that follows. MUSTARD SAUCE

3 tablespoons dijon mustard

1 teaspoon flour

1/4 teaspoon salt

1 cup cream (or milk)

1/4 cup sugar

1 egg yolk, beaten until thick

1/4 to 1/2 cup vinegar, heated

In a small bowl combine the mustard, flour, salt and 1/2 cup of the milk. In a heavy pan combine the rest of the milk and the sugar. Heat, and then add the mustard mixture. Stir a little of the hot mixture into the beaten egg yolk, then return it to the pot. Stir and cook until thick. Stir in the heated vinegar to taste. MARY'S ITALIAN TORTILLAS (2 servings

After a trip to the American Southwest, architect Mary Ossi came back to D.C. impressed with the number of ways flour tortillas are used in Tex-Mex cooking. Borrowing from her Italian heritage she came up with her own variation, the Italian tortilla. Or perhaps it should be called a Southwestern pizza.

4 flour tortillas

About 2 cups of grated cheddar cheese

2 small to medium zucchini, sliced

Salt

Pepper

Optional additional toppings: chopped onions or sliced scallions, diced tomato, chopped green pepper or ripe olive slivers

Preheat the oven to 350 degrees. Place the flour tortillas flat on a cookie sheet, browned side down. Sprinkle each with about 1/2 cup of shredded cheese, making sure that the cheese reaches all the way to the edges. (Otherwise the edges will curl and harden while cooking.) Place the zucchini circles on top of the cheese. Sprinkle with salt and pepper. Add any of the other toppings you wish. Put the tortillas in the oven and heat for 10 to 15 minutes, or until the cheese melts and begins to bubble and brown. The tortillas can be served flat and eaten with a knife and fork, but the easiest way is to roll each tortilla into a tube, carefully holding up the end with your little finger while eating to prevent it from dripping. PASTA WITH CLAM SAUCE (6 servings)

1/4 pound butter

2 to 3 cloves garlic

2 to 3 tablespoons flour

4 7 1/2-ounce cans minced clams

1/4 cup fresh chopped parsley

2 teaspoons dried thyme leaves

Freshly ground black pepper

1 pound pasta, cooked

Melt the butter in a saucepan. Put the garlic through a garlic press, using 2 to 3 cloves, depending on how much you like garlic. Add garlic to the butter and cook 1 minute over low heat. Using a wire whisk, stir in the flour. (Two tablespoons makes a thin sauce; 3 tablespoons makes a medium sauce.) Drain the juice from the 4 cans of clams into a bowl. Add the juice to the flour and garlic mixture, stirring all the while. Add the parsley, thyme and pepper, and simmer gently for 10 minutes. When you are ready to serve, heat the mixture to a boil, and add the clams just long enough to heat through (if the clams are boiled they'll become tough). Serve over the pasta. JACK AND GIGI'S BURRITOS (4 to 6 servings)

On the lookout for a quick and tasty dinner, Gigi Pickford and Jack Barse tried a commercial burrito kit from the grocery store. They decided the idea was good, but that the seasoning in the kit wasn't. So they developed their own burrito recipe. According to Barse, a technical specialist for Xerox Corp., "A good Mexican burrito doesn't burn immediately -- it waits." The version given below, however, is carefully gauged to provide only a medium amount of heat. That's the fire level Pickford (a newsletter editor for the Council on Foundations) likes for her burritos.

10 refrigerator flour tortillas

1 pound ground beef

2 cloves garlic, pressed

2 1/2 tablespoons hot chili powder

3/4 cup chopped onion

Salt

Pepper

1-pound can tomatoes

Condiments: sour cream, grated cheddar cheese, diced tomato, chopped onion, shredded lettuce and bottled taco sauce

1-pound can refried beans

Preheat the oven to 250 degrees. Remove the flour tortillas from their package, wrap the entire stack in a damp kitchen towel and place in the oven. While they are being warmed, begin browning the ground beef in a large skillet. As it browns add the pressed cloves of garlic, 1/2 tablespoon chili powder and chopped onion, salt and pepper to taste. After the meat has browned, drain off the fat.

Next add the can of tomatoes to the meat, breaking up the tomatoes with a spoon while the mixture continues cooking. Add 2 tablespoons chili powder, and, stirring occasionally, simmer uncovered for about 15 minutes or until the mixture thickens.

While the mixture is simmering, prepare the burrito condiments: sour cream, grated cheese, diced tomatoes, shredded lettuce and chopped onion. After the meat mixture has thickened, add the can of refried beans, stirring it into the mixture and heating thoroughly.

Remove the tortillas from the oven and construct each burrito in the following manner: Place a flour tortilla flat on a plate, browned side down. Spread 1 tablespoon of sour cream over it. Put approximately 3 tablespoons of the meat and bean mixture in a strip on one side of the tortilla. Sprinkle with grated cheese and bottled taco sauce. Add the other condiments to taste, fold over the tortilla and roll it up. Place the finished burritos in the oven to keep warm until serving time.