In a small cast iron pan, put the meatballs and cover them with tomato sauce.
Cook in the oven until the sauce is splashing.
Add the mozzarella on top and place again in the oven, until the mozzarella has completely melted.
Serve the cast iron pan on a wooden tray with a serviette under the pan. Place the pan slightly close to the tray’s handle, but place the pan’s hot handle away from the tray’s handle, to avoid servers and customers getting burnt.
Add a few basil leaves, and optionally, a drizzle of olive oil.