Heat barbeque grill. In a small bowl, combine all glaze ingredients; mix well. Sprinkle pepper on both sides of chicken.
When ready to barbeque, place chicken on gas grill over low heat or on charcoal grill 4-6 inches from medium coals. Cook 5 minutes. Turn chicken and place onion slices on the grill; brush chicken and onions with glaze.
Cook an additional 5-10 minutes or until onions are tender and chicken is no longer pink and juices run clear, brushing frequently with glaze. Heat any remaining glaze to a boil; serve with chicken.
BROILER INSTRUCTIONS:
Spray broiler pan with nonstick cooking spray. Prepare glaze and chicken as described above. Arrange chicken on spray-coated pan; brush chicken with glaze. Broil 4-6 inches from heat for 5 minutes. Turn chicken and place onion slices on top, brush chicken and onion slices with glaze. Broil an additional 5-6 minutes, or until onions are tender and juices run clear, brushing frequently with glaze. Heat any remaining glaze and serve with chicken.