- Place chicken in large plastic food storage bag; pour in teriyaki sauce. Press air out of bag; close top securely. Refrigerate 8 hours or overnight, turning bag over occasionally.
- Reserving marinade, remove chicken and place on rack of broiler pan. Add enough water to reserved marinade to measure 1-1/4 cups.
- Heat oil in 2-quart saucepan over medium-high heat. Add onion, celery and garlic; sauté 2 minutes. Pour in teriyaki mixture; bring to boil. Skim off foam. Stir in barley and tomato; cover and simmer 1 hour.
- Meanwhile, broil chicken 5 to 6 inches from heat source 35 to 40 minutes, or until chicken is no longer pink near bone; turn chicken over every 10 minutes.
- Uncover saucepan; simmer 10 minutes longer.
- Just before serving, stir parsley into barley mixture and serve with chicken.