Potato Onion Casserole
["4 to 5 potatoes, thinly sliced", "4 to 5 small onions, thinly sliced", "1 can cream of mushroom soup", "3/4 c. milk", "2 Tbsp. margarine"]
["Alternate potatoes and onions in layers in a greased 2-quart casserole dish. Add salt and pepper to each layer.", "Combine soup and milk.", "Pour over layers. Dot with butter and bake at 350\u00b0 for 40 to 50 minutes."]
["potatoes", "onions", "cream of mushroom soup", "milk", "margarine"]