Corned beef is to St. Patrick's what turkey is to Thanksgiving

Whether or not we are of Irish descent, St. Patrick's Day seems to be a day for conviviality. We don green carnations, sing the songs of old Erin, and plan a menu or eat foods that have come to be associated with the sons and daughters of the Emerald Isle. Cabbage, potatoes, and bacon are some of the simple Irish foods, and no Irish meal is complete without Irish soda bread, a round, yeastless bread made with flour, baking soda, and buttermilk.

Corned beef and cabbage is always the favorite on this holiday, and it's fairly easy to serve with boiled white potatoes or perhaps with additional vegetables. Sweet potatoes would be a change from the usual and another variation would be to add an apple garnish. Another change might be to stuff the cabbage with a mixture of rice and seasonings.

Whether you serve your corned beef and cabbage plain or with some new variation, it's still as traditional as turkey on Thanksgiving Day. But although there are numerous recipes for ways to use leftover turkey after a big dinner, there aren't as many for leftover corned beef.

Here are a few that offer a little change from the ubiquitous but delicious Reuben Sandwich, and the traditional corned beef hash. All are suitable for brunch, lunch, or light supper. Sons of Erin Soup 1/2 cup chicken broth 1/2 cup beef broth 1/4 cup chopped celery 1/4 cup chopped onion 1/4 cup chopped green pepper 1 tablespoon cornstarch dissolved in 2 tablespoons water 1 cup shredded cooked corned beef 1 cup chopped Swiss cheese 3/4 cup sauerkraut, drained, rinsed, and squeezed dry 1/4 cup butter or margarine 2 cups half-and-half or evaporated milk Salt Freshly ground pepper

In a heavy saucepan, bring to a boil the broths, celery, onion, and green pepper. Reduce heat and simmer until vegetables are crisp-tender, about 5 minutes.

Blend in dissolved cornstarch and cook until soup thickens, about 5 minutes. Remove from heat. Add corned beef, cheese, and sauerkraut.

Melt butter in top of double boiler set over gently simmering water. Blend in half-and-half. Add soup and stir until smooth and heated through. Do not boil. Season with salt and pepper. Serve immediately. Serves 6 to 8. Corned Beef Pasties 2 cups plus 2 tablespoons flour 1 teaspoon baking powder 1/2 teaspoon salt 6 tablespoons shortening 1 egg yolk, beaten 1/3 cup milk 1/2 cup chopped onion 2 tablespoons butter or margarine 11/2 cups cooked ground corned beef 11/2 cups canned tomatoes Salt and pepper to taste

Sift 2 cups flour, baking powder, and salt together. Cut in shortening as for pie dough. Blend egg yolk into milk. Work into flour mixture.

Divide dough in two parts. Roll each part on floured board or pastry cloth into an oblong large enough to cut into 8 squares of pastry approximately 31/2 to 4-inches wide.

Line cupcake pans with pastry squares. (Do not cut off corners of pastry.)

Brown onion in butter. Add corned beef. Add remaining flour, then tomatoes, salt, and pepper. Cook together until thickened.

Spoon hot mixture into pastry-lined pans. Turn corners of pastry over mixture loosely. Bake at 450 degrees F. for 10 minutes. Allow to stand in pans 10 minutes after baking to make them easier to remove. Serves 6 to 8. Corned Beef and Pasta Casserole 1/2 cup mild cheese, diced 1 cup milk, scalded 1 103/4-ounce can condensed cream of chicken or mushroom soup 1 small onion, shredded Salt to taste 1 8-ounce package noodles, macaroni, or other pasta, cooked and drained 11/2 cups cooked shredded corned beef 2 cups cereal flakes 1/2 cup butter or margarine, melted

Add cheese to milk. Stir until cheese is melted. Add soup. Blend well. Add onion, salt, noodles, and corned beef. Mix well. Pour into casserole.

Sprinkle with cereal flakes. Pour butter over top. Bake at 350 degrees F. for 45 minutes. Serves 8 to 10.