Prick potatoes with a fork; cook in a microwave until tender. Meanwhile, in a large skillet, cook beef and green pepper with onion until meat is no longer pink; crumble meat; drain. Stir in tomato and pizza sauce; heat through. , Split potatoes lengthwise; flake potato centers with a fork. Spoon meat mixture into each; top with mozzarella cheese. Sprinkle with herbs if desired.