Potatoes
Onion
Bacon fat
Flour
Water or milk

Peel and slice potatoes; slice onion. Lay potato slices and onion rings alternately in casserole dish. Make gravy: Brown flour in bacon grease; add water or milk until it is as thin as you like. Pour over potatoes and onion. Bake at 350 degrees until tender, about 1 1/2 hours.