In a large bowl, place beef mince, Greek seasoning and ¼ cup of the pasta sauce. Season with black pepper and mix well. Roll into 20 walnut-sized meatballs.
Spray a large non-stick pan with oil and set over medium-high heat. Cook meatballs in batches until browned all over. Transfer to a plate. Add onion, carrot, celery, and half the garlic to the pan. Cook, strirring,for - minutes until softened. Add the remaining pasta sauce with 1 ½- 2 cups water. Bring to the boil. Reduce heat, simmer covered for 5-10 minutes. Add meatballs, simmer for 2-3 minutes. Stir in spinach.
Meanwhile, heat a chargil pan. Combine oil and remaining garlic, and brush mizture over both sides of the bread. Grill in pan for 1-2 minutes each side or until golden and smoky.
Divide meatballs amon plates. Serve with garlic bread.