Home-Style Scalloped Potatoes

1/3 cup chopped onion
5 tablespoons butter or margarine
5 tablespoons all-purpose flour
1-1/4 teaspoons salt
1/2 teaspoon pepper
5 cups milk
6 cups thinly sliced potatoes

In a large saucepan, saute onion in butter until tender. Stir in flour, salt and pepper until blended. Gradually add milk. Bring to a boil; cook and stir for 2 minutes or until sauce is thickened.

Place half of potatoes in a greased 3-qt. baking dish. Pour half of sauce over potatoes. Repeat layers. Bake, uncovered, at 350° for 60-70 minutes or until potatoes are tender and top is lightly browned. Serve immediately. Makes 8 servings.