Spray full-size sheet pan with pan coating. Spread vegetables in single layer in pan. Sprinkle with salt and pepper. Spray lightly with nonstick cooking spray. Bake in 400°F oven for 20 to 30 minutes or until vegetables begin to brown.
Spread dressing on cut-sides of focaccia. Layer bottom half of each focaccia with roasted vegetables and Swiss and American cheese slices. Broil until cheese is melted. Sprinkle with basil; cover with top half of focaccia.
Cut each focaccia into 6 sandwiches.