Scalloped Potatoes
["1/4 c. chopped onion", "1/4 c. butter or margarine", "1/4 c. all-purpose flour", "2 1/2 c. milk", "5 large potatoes, peeled and thinly sliced"]
["To make sauce, cook onion in butter or margarine until tender, but not brown.", "Stir in flour, 1 1/2 teaspoons salt and 1/8 teaspoon pepper.", "Add milk.", "Cook and stir until thickened and bubbly.", "Cook and stir 1 to 2 minutes more.", "Remove from heat."]
["onion", "butter", "all-purpose", "milk", "potatoes"]