Mashed Potatoes
In a bowl, place the ground beef, the onion, parsley and chives, the breadcrumbs and salt to taste, mix it all together very well to season the meat. Using a tablespoon, shape the meat into balls (meat balls), make them the size of a tablespoon, round them and take them to fry on low heat. Set aside.
Into a pan, add the precooked and well mashed potatoes, add the butter, the milk, and salt to taste, mix for 2 minutes.
To assemble, transfer the mashed potatoes to a baking dish, spread evenly over the bottom. Place the meat balls over the mashed potatoes, spread some tomato sauce over the meat balls and top it all with shredded mozzarella cheese.
Bake in a preheated oven at 180°C (356°F) for 20 minutes.