Old Fashioned Scalloped Potatoes

3 tablespoons butter

3 tablespoons flour

1 1/2 teaspoon salt

1/4 teaspoon pepper

3 cups milk

9 medium potatoes

2 tablespoons minced onion

1 1/2 cup American cheese

In 2 quart saucepan over medium heat, melt butter. Stir in flour, salt and pepper until blended; continue cooking 2 minutes, stirring constantly. Gradually stir in milk and cook until sauce is thickened and smooth, stirring constantly. Remove from heat and set aside; stirring occasionally to keep skin from forming on sauce surface. Peel potatoes, slice thinly. In greased 2-quart baking dish, arrange 1/2 the potatoes, sprinkle with 1/2 the onion; pour 1/2 sauce over top. Repeat with remaining potatoes, onion and sauce. Cover with aluminum foil and bake at 350 degreed for 1 hour. Uncover and bake for 1 hour longer or until potatoes are fork tender and top is brown.