Peel potatoes and slice very thin.
Preheat oven to 350 degrees.
In a bowl combine salt and flour. Dredge potato slices in
the flour mixture. Place potatoes in a 2 quart casserole
In a saucepan sauté onion in butter until tender.
Add buttermilk to pan and heat through; do not boil. Pour
mixture over potatoes, grind pepper or paprika over the top.
Bake for 1 hour, or until potatoes are tender.