1. Place flour, egg and bread crumbs in three separate bowls. Cut each mozzarella stick into thirds. Coat each piece in flour, then egg, then crumbs. Heat oil in a large frying pan over a medium flame. Fry cheese sticks on both sides until golden.
2. Mix dressing ingredients together. Combine tomatoes, onion, and fried mozzarella sticks and pour dressing over them. Toss and serve immediately.