Some cooks soak the stale bread in water for a few minutes and then squeeze it dry before combining it into a mash with the eggs and cheese, then shaping the mixture into balls. Some opt not to use the crust of the bread.
The recipe below, from the newly released "Food of the Italian South" by Katie Parla (Clarkson Potter, $30), calls for cooking the meatballs directly in the fresh tomato sauce. Another option is to fry the balls first in a little olive oil, to give them some browning, and then add them to the sauce. No matter which way you go, let these dumpling-esque balls simmer in the sauce until they are plump, spongy and tender. The recipe calls for a 15-minute heat treatment. I had better results when I let them sit in the pan for nearly half an hour.