THE JOYS of the brimming chowder pot can be traced to the sea coast of Brittany. In the early days, French fishermen would return to their villages with their catches, and each would contribute a part of his to la chaudiere. They would faire la chaudiere or prepare the cauldron with a variety of fish and shellfish, simmering the cauldron on the beach. The result was a hearty seafood stew which everyone shared.

The earliest seafood chowders were just that: seafood simmered in a large pot, with water and sometimes wine added, and probably herbs, onions and spices.

When French fisherman emigrated to Nova Scotia, they brought the custom of preparing the cauldron with them. As the custom spread down the American seacoast, it is easy to see how chaudiere became anglicized to chowder.

Chowders belong naturally to seacoast areas. But chowders have become so popular they are regularly seen on inland menus, and have branches out from the traditional seafood stew or soup to include such things as vegetable and poultry chowders.

Eventually, American chowders came to include milk or tomatoes in the base.On Long Island, where fish and truck farms abounded, cooks added the plentiful tomato and potato to their seafood stocks. This rich combination also came to include carrots, celery and a variety of seasonings. It was a substantial chowder, and summer visitors to Long Island beaches raved about it in New York, where it soon appeared as Manahattan Clam Chowder or simply Manhattan Chowder.

In New England, where rocky meadows were more suitable for dairy farming than truck farming, milk and cream were abundant, and they were added to the chowders. The controversy still rages as to which is the superior chowder.

The dispute will never be settled, for seafood chowder can and should include whatever is fresh and abundant. Fishermen and cooks should not hesitate to substitute one fish for another. A cook should buy the seafood that is seasonal and most economical. Prepared with care, chowder is a robust main dish, redolent of the ocean's bounty, the garden's plenty, with a milk or tomato base and spices and seasonings. Just as the original chowders were a happenstance mixture, so chowders today should be democratic and freewheeling.

Seafood chowder is a marvelous one-dish meal for a crowd. With French bread or sea biscuits, jug wine and a light dessert, a brimming chowder pot is a sure coup. FISH CHOWDER BRIDGEHAMPTON 2 pounds any white-fleshed fish 1/8 pound salt pork 3 small onions, chopped 4 pilot crackers, broken Water Salt, pepper, nutmeg, cayenne 2 tablespoons catsup 1 pint white wine

Cut the fish into 2-inch pieces. Fry the salt pork together with the onions. Place fish into a saucepan and just cover it with water. Add the onions and salt pork, the pilot crackers and the seasonings to taste. Cook gently for 30 minuntes. Then add the catsup and wine; simmer 15 minutes more. Serve at once. LAZY DAY NEW ENGLAND STYLE CLAM CHOWDER (4 servings) 1 can (8 ounces) minced clams 1 can potato soup 1 cup milk 2 bay leaves 2 grinds of pepper

Put all ingredients in double boiler and stir over low heat. Ready in about 15 minutes. CHESAPEAKE CRAB CHOWDER (12 servings) 1 cup chopped onion 1 cup chopped celery 6 tablespoons butter 2 cans crab meat (7 1/2 ounce size) 6 cups milk 2 cans potato soup 2 cans creamed corn (8 ounce size) 1/4 cup chopped pimento 1/2 teaspoon salt 1/4 teaspoon thyme 2 bay leaves 1/2 cup dry vermouth 1/2 cup snipped parsley

In large kettle cook onions and celery in butter. Add drained, flaked crab meat and remaining ingredietns except vermouth and parsley. Heat thoroughly (15 minutes), then stir in vermouth and heat 2 minutes more. Remove bay leaves, garnish with parsley. LA CHAUDIERE BRITTANY 1/4 pound salt pork, cut thin 2 or 3 pounds fish (any firm-fleshed fish, sliced) Salt and pepper Herbs and spices to taste (dried thyme, chopped parsley, basil, etc.) 5 to 6 potatoes, sliced thick Ship biscuits or pilot crackers, broken (also called Hard Tack)

Fry the slices of salt pork. Then put in a layer of fish which has been cut in slices and rubbed with salt and pepper. Then put in a layer of potatoes; then a layer of sea biscuits or pilot crackers. Then begin all over again and make another series of layers. Add water and seasonings and cook slowly for one hour. MANHATTAN CLAM CHOWDER 1/4 pound salt pork, diced 48 hard shelled clams, chopped 2 cups celery, chopped 2 onions, chopped 3 large fresh tomatoes, coarsley chopped (or 1 large can) Salt and freshly ground black pepper Dried thyme and basil leaves for seasoning (optional)

This chowder is better if made one day and eaten the following day, after flavors have blended and mellowed. Heat iron kettle and fry out salt pork. Put in chopped clams and clam liquor. Add to this celery, onions, tomatoes and seasonings. Simmer -- do not boil -- over low heat for about 6 hours. Stir occasionally. Take pot off heat and cool the chowder in open air. Reheat to serve, but again -- do not allow it to boil. SHRIMP CHOWDER 1/4 cup diced salt pork 1 large onion, chopped 1 cup diced celery 1 quart boiling water 1 quart diced, cooked potatoes 2 teaspoons salt 1/4 teaspoon celery salt 2 cups prepared shrimp 1 pint milk 1 tablespoon flour 1 tablespoon butter Paprika 1 teaspoon minced parsley

Fry pork in iron kettle. Remove crispy bits and cook onion in fat. When onions are yellow, add celery and boiling water.Cook 15 minutes, then add potatoes, salt, pepper and celery salt. Let all come to a boil and add shrimp. Cook 15 minutes longer and add milk. When at a boil, thicken with flour and butter blended with a little cold milk. wPour into serving dishes and sprinkle with paprika and finely minced parsley.