3 tbsp. butter
3 tbsp. flour
1 1/2 tsp salt
1/4 tsp. pepper
3 c. milk
9 medium potatoes
2 tbsp. minced onion
1 1/2 c. 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 the 1/2 onion; pour 1/2 sauce over top. Repeat with remaining potatoes, onion, and sauce.

Cover with aluminum foil and bake at 350°F for 1 hour. Uncover and bake for 1 hour longer or until potatoes are fork tender and top is brown.