1. Prepare outdoor grill with medium-hot coals, or heat gas grill to medium-hot, or heat oven broiler. Lightly coat grill rack or broiler-pan rack with nonstick cooking spray.
2. Saute onion in oil in small non-stick skillet over medium-low heat until softened, about 10 minutes; do not let brown. Remove from heat.
3. Tear 1 hamburger bun into pieces and place in food processor. Whirl until fine crumbs form.
4. Mix together the ground chicken, egg, barbecue sauce, salt, pepper, crumbs and sauteed onion in medium-size bowl. Stir in corn kernels. Shape into 6 equal patties.
5. Grill or broil patties about 4 inches from heat, turning once, for 10 minutes or until instant-read thermometer inserted in centers registers 165 degrees F. Serve on soft roll with sliced red onion and extra barbecue sauce.