Wash, peel, and slice the potatoes thinly. Chop the onion.

In a large skillet, heat olive oil over medium heat. Sauté the onion for 3-4 minutes until translucent. Add ground beef and cook until browned. Drain excess fat and stir in garlic powder, salt, black pepper, and paprika.

In a greased 9x13 inch baking dish, layer half of the sliced potatoes, half of the beef mixture, half of the cream of mushroom soup mixed with milk, and half of the cheese. Repeat layers.

Cover with aluminum foil and bake in a preheated oven at 350°F for 45 minutes. Remove foil and bake for an additional 15 minutes until cheese is bubbly and golden.

Let the casserole cool for 5-10 minutes before serving.