POTATOES AU GRATIN

1 medium onion, chopped (about 1/2 cup)
2 tablespoons margarine or butter
1 tablespoon flour
1 teaspoon salt
1/4 teaspoon pepper
2 cups half-and-half*
2 cups shredded natural sharp Cheddar cheese (about 8 ounces)
6 medium potatoes, sliced
1/4 cup fine dry bread crumbs

Heat oven to 375 degrees: Cook and stir onion in margarine in 2-quart saucepan until onion is tender. Stir in flour, salt and pepper. Cook over low heat, stirring constantly, until mixture is smooth and bubbly; remove from heat. Stir
in half-and-half and 1-1/2 cups of the cheese . Heat to boiling, stirring constantly. Boil and stir 1 minute. Place potatoes in ungreased
1-1/2 quart casserole. Pour cheese sauce on potatoes. Bake uncovered until top is brown and bubbly, 1-1/4 to 1-1/2 hours.
Mix remaining cheese and the bread crumbs; sprinkle over casserole. Set oven control to broil and/or 550 degrees: Broil with top 3 to 4 inches from heat until top is crusty and light brown, about 4 minutes.
6 servings.

* 2 cups milk and 2 tablespoons margarine or butter can be substituted for the half-and-half.

Tip: Broiling step can be omitted. Bake casserole uncovered 1 hour; sprinkle with cheese-crumb mixture. Bake until top is brown and bubbly, 15 to 30 minutes.