01 - Combine ground turkey, egg, breadcrumbs, Parmesan cheese, parsley, garlic, oregano, salt, pepper, and milk in a large bowl, mixing gently until just combined to avoid toughening the mixture.
02 - Shape the mixture into 16 equal-sized meatballs, approximately 1.5 tablespoons each.
03 - Heat olive oil in a large skillet over medium heat and brown meatballs on all sides for 5 to 7 minutes; remove and set aside.
04 - In the same skillet, add olive oil and cook chopped onion over medium heat until soft, about 4 minutes, then add garlic and cook for an additional minute.
05 - Add crushed tomatoes, dried basil, oregano, sugar, salt, and optional chili flakes to the skillet; stir and bring the sauce to a simmer.
06 - Return browned meatballs to the skillet, nestling them into the sauce, cover, and simmer on low heat for 20 minutes until cooked through.
07 - Garnish with fresh basil and serve hot alongside pasta, rice, or crusty bread.