Combine turkey, egg, onion, garlic, parsley and breadcrumbs in a large bowl.
Season with a bit of salt and pepper. Mix thoroughly with your hands. Scoop out into large golf size meatballs.
Heat a large skillet with oil. Add meatballs in batches and cook until browned. 2-3 minutes on each side.
Add in tomato sauce and simmer until the meatballs are cooked through, 5-10 minutes.
Turn off the heat and sprinkle with cheese.
Broil until the cheese is melted.
Top with basil and serve immediately with pasta!