Lightly oil a 9 by 13 baking pan. Slice potatoes & onions 1/4 inch thick. Mix Potatoes, onions, and Ham together then place in baking pan. Mix soup and milk together with a dash of salt & pepper to taste. Pour soup mix over potoatoes and ham in baking dish, top with graded chesse. Bake at 375 for about 45 minutes until hot though and cheese is lightly browned. Serves 6 by its self, add a veggie and will serve 8 or more.
I've added bell peppers, veggies, to this and it's still great. Use Chicken instead of ham and it works as well. I make this for pot lucks at work during the winter, and every one loves it.