Put the bread in a small mixing bowl, cover with milk, and leave to soak.
Chop the parsley and garlic together. Put meat into a large mixing bowl. Squeeze the milk out of the bread and add to meat. Add parsley and garlic. Use your hands to mix the ingredients. Break eggs into the mixture to bind it. Keep mixing. Add the pecorino. Season with salt and freshly ground black pepper. Shape meatballs by hand, make a hole in the top and insert a small piece of mozzarella. Cover it up and pat meatball into shape. Roll them in bread crumbs. Pour olive oil into a frying pan and when it’s really hot, fry the meatballs for 5 minutes, or until they have formed a crust. Then turn over. When golden brown and crusty on both sides remove the meatballs from the pan and drain on paper towels.
Add the meatballs to the tomato sauce, cover and cook very slowly on low heat for 45 minutes, until the sauce is reduced by half.
Pour enough oil into a saucepan to cover the surface. Add garlic and 3 tins of tomatoes, mashing them slightly. Boil the sauce for 5 minutes and simmer for another 3 minutes.