3 tablespoons fresh grated Parmesan cheese (omit for Whole30)
1 tablespoon chopped fresh parsley
Heat slow cooker on low setting. Add the sauce to the slow cooker and cover.
Combine all of the ingredients for the meatballs in a large mixing bowl and mix until all ingredients are well incorporated.
Form the mixture into 30 evenly sized meatballs (about 2 inches).
Heat a large skillet over medium-high heat. Sear the meatballs, in batches, until they are evenly browned all over. (Alternatively, you can add the uncooked meatballs directly to the sauce in the slow cooker.)
Add the meatballs to the sauce in the slow cooker and let cook for 6 hours.