01 - In a large mixing bowl, combine ground turkey, breadcrumbs, Parmesan, egg, minced garlic, fresh parsley, dried oregano, salt, black pepper, and milk. Gently mix until ingredients are just incorporated without overworking the mixture.
02 - Shape the mixture into 16 to 18 evenly sized meatballs to ensure uniform cooking.
03 - Heat 2 tablespoons of olive oil in a large skillet over medium heat. Add meatballs in batches and cook until browned on all sides, about 5 minutes total. Transfer browned meatballs to a plate to rest.
04 - In the same skillet, heat 2 tablespoons of olive oil. Add the finely chopped onion and cook until softened, approximately 4 minutes. Add minced garlic and sauté for an additional 1 minute, stirring frequently.
05 - Stir in crushed tomatoes, dried basil, dried oregano, sugar if desired, salt, and black pepper. Bring the sauce to a gentle simmer over medium heat.
06 - Carefully add the browned meatballs into the simmering marinara. Cover and reduce heat to low. Let simmer for 20 to 25 minutes, or until the internal temperature of the meatballs reaches 165°F.
07 - Taste and adjust seasoning with additional salt or pepper if needed. Optionally stir in fresh basil. Serve hot alongside pasta, polenta, or crusty bread.