1/4 cup chopped onion
1/4 cup butter
1/4 cup all purpose flour
1 tsp salt
1/8 tsp pepper
2-1/2 cups milk
3/4 cup shredded american cheese
5 large potatoes, peeled and thinly sliced (5 cups)
Recipe
To make sauce, cook onion in butter til tender but not brown. Stir in flour, salt & pepper. Add milk. Cook and stir til thickened and bubbly. Cook and stir 1 to 2 minutes more. Add cheese & stir until melted. Remove from heat.
Place half of the sliced potatoes in a greased 2-quart casserole. Cover with half the sauce. Repeat layers.
Bake, covered, in a 350 oven 45 minutes, stirring once. Uncover, bake about 30 minutes more or til potatoes are done.