Gather all ingredients. Preheat oven to 350 degrees F (175 degrees C).
Heat a large skillet over medium-high heat. Cook and stir ground beef in the hot skillet until browned and crumbly, 5 to 7 minutes. Drain and discard grease.
Mix condensed soup, milk, onion, salt, and pepper in a medium bowl until combined.
Alternately layer the potatoes, soup mixture, and browned ground beef in a 2-quart baking dish. Cover the dish tightly with foil.
Bake in the preheated oven until potatoes are tender, about 1 to 1 ½ hours.
Remove foil, sprinkle Cheddar cheese on top, and continue baking until cheese is melted and bubbly, 5 to 10 minutes.
Serve and enjoy.
