In a large saucepan, melt butter over medium-low heat; stir in flour
until smooth and bubbly. Stir in salt and pepper. Gradually add milk,
stirring until thick and bubbly. Add sliced potatoes to the sauce.
Cover and simmer for 8 minutes.
Transfer mixture to a greased 12x8-inch baking dish. Bake, uncovered,
at 375° for 45 minutes, or until potatoes are tender.
Scalloped potatoes serves 6 to 8.