01 - In a large bowl, combine ground turkey, breadcrumbs, Parmesan, egg, garlic, onion, parsley, oregano, salt, pepper, and milk. Mix gently with your hands until just combined; avoid overmixing.
02 - Form the mixture into 16 golf ball-sized meatballs of uniform size.
03 - Heat olive oil in a large skillet over medium heat. Brown the meatballs in batches, turning to brown all sides, approximately 5 minutes.
04 - Remove excess oil if necessary. Add all browned meatballs back to the skillet.
05 - Pour marinara sauce over the meatballs. Add basil and red pepper flakes. Gently stir to coat evenly.
06 - Cover and simmer on low heat for 20 to 25 minutes, until meatballs are cooked through with an internal temperature of 165°F.
07 - Taste sauce and adjust salt and pepper as needed. Serve hot, garnished with extra parsley and Parmesan if desired.