Fry the beef in a nonstick pan, and when finished, drain off the fat and set it aside Place the potatoes in a medium sized mixing bowl, mash them, or if using the instant, follow the directions on the box.
Add the milk and whip them until creamy.
In a medium sized baking dish, place a layer of the whipped potatoes about an inch thick. Add all of the ground beef for the second layer. Add half of the cheese for the third layer. Use the rest of the potatoes for the fourth layer. Add the rest of the cheese on top.
Place in oven and bake at 350°F until the cheese is melted and you see part of the potatoes golden brown.