Preheat your oven to 375°F (190°C) and grease a baking dish with nonstick spray.

In a skillet over medium heat, cook the ground beef with the onion and garlic until browned, about 7–10 minutes. Drain excess fat.

In a bowl, mix the cooked beef with cream of mushroom soup, milk, salt, and pepper until well combined.

Layer half of the sliced potatoes in the baking dish followed by half of the meat mixture and half of the cheese. Repeat layering.

Cover with foil and bake for 45 minutes. Remove foil and bake for an additional 15 minutes until golden brown on top.

Allow to cool slightly before serving.