1 med. chopped onion (about 1/2 c.)
2 tbsp. butter
1 tbsp. flour
Salt and pepper
2 c. half and half
2 c. shredded sharp Cheddar
6 med. potatoes, sliced
1/4 c. fine dry bread crumbs

Heat oven to 375 degrees F. Cook and stir onion in butter 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 or 550 degrees F. Broil with the top 3 to 4 inches from heat until top is crusty and light brown, about 4 minutes.