Preheat oven to 450F
Mix ground beef, pork, bread crumbs, egg, Parmesan cheese, salt, pepper, chopped oregano and basil in a large mixing bowl. Divide into 12 equal parts and shape into 12 balls.
Heat the oil in a 12-inch cast iron pan. Add the meatballs and cook over medium-high heat, turning, for about 5 minutes or until browned all over.
Add the pasta sauce and bring it to the boil. Add the cheese.
Transfer the pan into the oven. Bake at 425F convection or 450F regular, uncovered, for 15 to 20 minutes or until meatballs are cooked through (reached internal temperature of 165F).
Remove the pan from the oven. Garnish with the remaining whole basil leaves, sprinkle some freshly ground black pepper on top and serve immediately.