01 -
Chop potatoes into thin slices (about ⅛-inch thick). Place them in a bowl of water to keep them from browning.
02 -
Set the oven temperature to 350°F. Grease a 9x13-inch baking dish lightly with cooking spray and keep it aside.
03 -
On medium-high heat, brown the ground beef with diced onions and garlic in a large pan. Break it into small pieces as it cooks. Drain the excess grease.
04 -
In a medium-sized bowl, stir together the cream of mushroom soup, onion powder, half-and-half, kosher salt, and black pepper. Make sure the mixture is smooth.
05 -
Once the potato slices are drained, layer ⅓ of the potatoes in your baking dish. Top them with ⅓ of the cooked beef mixture, ¾ cup of cheese, and ⅓ of the soup blend. Repeat the layering process one more time.
06 -
Finish it off with the remaining potatoes and beef mixture. Pour the soup mixture over the top, then scatter 1½ cups of cheese across it.
07 -
Cover everything tightly with foil and pop it into the oven for 70 minutes. Remove the foil and bake for 20 more minutes. Let the casserole cool for about 15 minutes before eating.