Combine first 6 ingredients in a small bowl. Reserve 1/4 cup mixture. Place remaining mixture in a large heavy-duty zip-top plastic bag; add fish. Seal and marinate in refrigerator at least 30 minutes, turning once.
Remove fish from marinade, discarding marinade.
Place fish on grill rack coated with cooking spray; grill 3 minutes on each side or until fish is medium-rare or desired degree of doneness. Transfer fish to serving plates; spoon reserved soy sauce mixture over fish and top with cilantro.