1Heat oven to 350ºF. Grease bottom and side of rectangular baking dish, 13x9x2 inches, with shortening.
2In very large bowl, mix soups, sour cream, milk and pepper. Stir in potatoes and onions. Spoon into baking dish.
3Bake uncovered 30 minutes. Sprinkle with cheese. Bake 15 to 20 minutes longer or until golden brown on top and bubbly around edges.