Ground turkey variation: 1 pound ground turkey, preferably dark meat, can be substituted for the beef and pork.
Make ahead: The meatballs can be shaped and refrigerated for up to 1 day before cooking. The meatballs can also be frozen uncooked or cooked. Arrange in a single layer on a baking sheet and freeze until solid. Transfer the meatballs to a freezer container or freezer bag, and freeze for up to 1 month. If uncooked, thaw in a single layer in the refrigerator overnight before cooking. If cooked, either thaw in the refrigerator overnight or thaw directly in simmering sauce for 15 minutes.
Storage: Leftovers can be refrigerated in an airtight container for up to 3 days or frozen for up to 1 month.