Makes 36 meatballs; serves 9-16 people, 2 per person for appetizers or 3-4 per person for an entrée.
Preheat the oven to 375°F.
Combine the pork, beef, bread, pork back fat, pancetta, parsley, 1 tablespoon of the salt, oregano, fennel pollen, black pepper and chili flakes in a bowl and mix. Place in refrigerator to stay cool and marinate for 30 minutes.
Grind meat mixture with meat grinder into a container.
In 2nd bowl, mix the ricotta, eggs, and milk. Put the ricotta mixture into the ground meat mixture and mix lightly until incorporated. Place into refrigerator for 1 hour for liquid to absorb into meat mixture.
Form the mixture into balls weighing approximately 1 1/2 to 2 ounces, and place on the parchment paper lined baking sheets. You should have about 35 meatballs.
Bake for 15 minutes. Remove from the oven and lower the oven temperature to 275° F.
Put the tomatoes and salt in a blender and coarsely blend to a sauce.
Put the sauce into a roasting pan and then place the meatballs into the sauce. Make sure meatballs are coated with the sauce. Add the basil leaves to sauce. Cover tightly with plastic wrap and then aluminum foil, and braise for 1 1/2 hours.
To serve, grate Parmigiano-Reggiano over the top. Could also be served with slices of grilled rustic country bread drizzled with olive oil.