How to Make It
Preheat broiler to high.
Cut bell pepper in half lengthwise; discard seeds and membranes. Place pepper halves, skin sides up, on a foil-lined baking sheet; flatten with hand. Broil 11 minutes or until blackened. Wrap pepper halves in foil. Let stand 5 minutes; peel. Cut into strips.
Place juice, oregano, oil, cumin, 1/4 teaspoon black pepper, ground red pepper, and beans in the bowl of a food processor; pulse 5 times or until coarsely chopped.
Heat a grill pan over high heat. Coat pan with cooking spray. Arrange zucchini and onion slices on pan; grill 5 minutes on each side.
Hollow out top and bottom halves of bread, leaving a 1-inch-thick shell. Spread black bean mixture over bottom half of bread; top with zucchini, onion, and bell pepper. Sprinkle with remaining 1/4 teaspoon black pepper, salt, and cheese. Top with top half of bread. Coat both sides of sandwich with cooking spray. Place sandwich on grill pan; top with a heavy skillet. Grill 3 minutes on each side or until cheese melts. Remove sandwich from pan; cut into quarters.