Brush cut side of the bottom bread half with mustard; brush cut side of top half with vinegar. Top bottom half with mozzarella, basil, ham, peppers, and tomato. Top with remaining bread half.
Heat a large nonstick skillet over medium heat. Coat pan with cooking spray. Add sandwich to pan; top with another heavy skillet. Cook 3 minutes on each side or until golden. Cut sandwich into 6 wedges.