Combine turkey, chicken, egg, bread crumbs, Italian seasoning, salt and pepper in a bowl. Gently work together with your hands until mixed.
Have a bowl of water handy. With wet hands, form 90 meatballs (rewetting hands as needed), using about 1 scant tbsp for each.
Heat 1 tbsp of the oil in a large skillet over mediumhigh heat. Brown one-third of the meatballs on all sides, shaking pan to maintain shape, for 5 minutes. Transfer to a platter; repeat twice more with remaining oil and meatballs.
Refrigerate meatballs in a resealable container. Save half for Italian Wedding Soup (page 136). Use remaining half for Rigatoni and Meatball Gratin.