Combine green onions cilantro, garlic, citrus zests and juices, soy sauce, oil, and salt in a food processor or blender until a coarse purée forms. Place chicken in a large, resealable plastic bag and pour marinade in. Seal bag, gently knead and turn bag to coat chicken pieces. Refrigerate for 20 minutes, up to 2 hours.
Heat grill or grill pan to medium-high heat (around 350-400 degrees), and remove chicken pieces with tongs and place on grill skin side down. Reserve marinade for later use.
Cook chicken, turning as needed, until cooked through (165 degrees F.)
Meanwhile, pour the reserved marinade into a small sauce pan and heat to boiling. Boil until sauce has reduced and thickened. Remove from heat and set aside.
Once chicken is cooked through, remove from grill and serve with the reduced sauce.