01 - In a large mixing bowl, combine the ground turkey, egg, breadcrumbs, Parmesan cheese, minced garlic, chopped parsley, dried oregano, salt, black pepper, and milk. Mix ingredients gently until just combined, taking care not to overmix the mixture.
02 - Form the meatball mixture into 16 uniform meatballs, approximately 1 1/2 inches in diameter.
03 - Heat 1 tablespoon of olive oil in a large skillet over medium heat. Arrange the meatballs in a single layer in the skillet and brown them on all sides for 5 to 6 minutes. The meatballs do not need to be cooked through at this stage. Remove the browned meatballs from the skillet and set them aside.
04 - Using the same skillet, add 1 tablespoon of olive oil. Sauté the finely chopped onion over medium heat for 3 to 4 minutes until it becomes translucent. Add the minced garlic and continue to cook for 1 minute until fragrant.
05 - Stir in the canned crushed tomatoes, dried basil, dried oregano, sugar (if using), salt, and black pepper. Bring the sauce to a gentle simmer.
06 - Carefully return the browned meatballs to the simmering marinara sauce. Cover the skillet and allow the meatballs to simmer gently for 20 to 25 minutes, or until they are thoroughly cooked. The internal temperature of the meatballs should reach 165°F (74°C).
07 - Taste the marinara sauce and adjust the seasoning as needed. Garnish with fresh basil, if desired, before serving hot over pasta, rice, or with crusty bread.