Step 1

Heat grill or grill pan. In large bowl, mix zucchini, mushrooms, bell pepper, onion, oil, thyme and salt; toss to coat vegetables. Place on grill over medium-high heat. Cover and cook 8 to 12 minutes, working in batches as necessary, until grill marks appear and vegetables are just crisp-tender. Set aside.

Step 2

Place focaccia halves on work surface, cut sides up. In small bowl, mix mayonnaise and pesto. Spread mayonnaise mixture on cut sides of bread. Layer zucchini, mushroom, bell pepper and onions on bottom half. Top with arugula, sundried tomatoes and cheese. Carefully replace top half; press slightly. Cut into 8 pieces, and serve.