You could substitute Italian Square Meatballs, for the purchased meatballs.
Potatoes can be prepared, covered with foil and refrigerated overnight. Bake covered at 350°F. for 45 minutes. Arrange meatballs in rows over potatoes; press in slightly. Sprinkle with remaining 1/2 cup cheese. Bake uncovered an additional 20 to 25 minutes or until golden brown and hot in center.