For a smoother meatball, grate the vegetables. Pecorino is much saltier than the Parmesan. If using Parmesan, use 2 very large five-finger pinches of salt. If using Pecorino, use 1 very large five-finger pinches of salt. For a great go-to meatball, try 1 pound ground beef, 1 pound ground turkey, 1 cup panko, 1 small carrot, 2 stalks celery and 1/2 onion.