ocr: 20 shrimp, shelled 1 red onion, cut into 1- inch cubes (there will be several layers sticking together, making it possible to skewer) 1r red bell pepper, seeded, and cut into 1-inch cubes 1 green bell pepper, seeded,and cut into 1-inch cubes 10 new potatoes, steamed and sliced in half 10 mushroom caps 1c.f fat-free barbecue sauce nonstick vegetable oil spray