1. Cut the zucchini, squash and eggplant into 1/4-in.-thick strips; spritz with cooking spray. Spritz onion and red pepper with cooking spray.
2. Grill vegetables, covered, over medium heat for 4-5 minutes on each side or until crisp-tender. Remove and keep warm. Grill buns, cut side down, over medium heat for 30-60 seconds or until toasted.
3. In a small bowl, combine the cheeses, garlic, salt and pepper; spread over bun bottoms. Top with vegetables. Replace bun tops. Yield: 4 servings.