- Stir together ingredients for marinade in a small bowl.
- Place skirt steaks in a shallow dish or bowl and pour marinade over top to evenly coat. Marinade for at least 1 hour and up to 4 hours.
- Heat grill or grill pan to high heat and grease with cooking oil. When grill reaches 500ºF, use tongs to remove steaks from marinade and place on grill, leaving the top open. Grill for 3-5 minutes on each side depending on doneness preference.
- Remove steaks from grill and rest for 5 minutes before slicing. Serve hot topped with additional green onion.