Heat oven to 350 Degrees. Peel and cut potatoes into thin slices. In a greased 2-quart casserole dish, arrange potatoes in 4 layers, sprinkling each of the first three layers with 1 TBLS onion, 1 TBLS flour, 1/4 TSP salt, dash of pepper, and dotting each with 1 TBLS butter. Sprinkle top with remaining onion, salt and pepper, and dot with remaining butter. Heat milk just to scalding; and pour over potatoes. Cover and bake for 30 mins. Uncover (Add Ham {optional}) Bake an additional 60-70 mins or until potatoes are tender. Let stand 5-10 minutes before serving