Preheat your oven to 350°F (175°C).

In a large skillet over medium heat, brown the ground beef for about 8-10 minutes, breaking it into small pieces.

Peel and thinly slice the small potatoes into uniform pieces, about ⅛ inch thick.

In a mixing bowl, combine the cream of mushroom soup with milk and whisk until smooth.

Grease a 9x13 baking dish with nonstick spray.

Layer the sliced potatoes, browned beef, half of the soup mixture, and a portion of the cheese in the dish; repeat layers and finish with cheese on top.

Cover with aluminum foil and bake for 1 hour.

Remove foil and bake for an additional 30 minutes until golden brown.

Let it rest for 10 minutes before serving.