Combine first 6 ingredients, stirring well with a whisk. Stir in 1 tablespoon oil. Place chicken in a zip-top plastic bag. Add vinegar mixture; seal. Marinate in refrigerator for 1 hour, turning once.
Preheat oven to 400F.
Remove chicken from bag; reserve marinade. Place marinade in a small, heavy saucepan over medium heat; bring to a boil. Boil 2 minutes or until syrupy, stirring frequently. Remove from heat; divide mixture in half. Heat a large ovenproof skillet over medium-high heat. Add remaining 1 tablespoon oil; swirl. Add chicken; saute 4 minutes. Turn chicken over; brush chicken with half of marinade mixture. Place pan in oven; bake at 400F for 6 minutes or until done. Remove chicken from oven; brush with remaining half of marinade mixture, turning to coat. Sprinkle with cilantro, if desired.