Cheesebuger Casserole 1 lb ground beef 1 onion, chopped 1/3 cup ketchup 2 tbs yellow mustard 1 cup cheddar cheese, shredded 8 slices bacon, cooked and crumbled 4 cups tater tots Heat oven to 400º. Brown meat with onions in skillet. Drain. Stir in ketchup and mustard. Spoon into 9-inch square baking dish sprayed with cooking spray. Top with remaining ingredients. Bake 30 to 35 min or until casserole is heated through and potato nuggets are golden brown.