Whisk all of the ingredients except for the steak together in a large mixing bowl.
Add the skirt steak to a large ziplock bag or baking dish. Then, add the marinade on top. If using a ziplock bag, store the sealed bag in a large mixing bowl before placing in the fridge to marinade in case it leaks. Or, if you’re using a baking dish, cover the dish with plastic wrap then place in the fridge.
Marinate the steak for at least 1 hour or up to 12 hours.
When ready to cook, sear the steak on each side for about 6-8 minutes on each side or until internal temperature reaches desired doneness.
Allow steaks to rest for 10 minutes after removing from heat. Then, slice the steak against the grain and serve immediately.
Notes
General internal steak temperatures based on doneness:
Rare: 120°–125°
Medium Rare: 130°–135°
Medium: 140°–145°
Medium Well: 150°–155°
Well Done: 160°–165°
For skirt steak, it’s generally recommended to be medium-rare to medium for best texture. Pull the steaks from the grill about 5 degrees before your preferred temperature using an internal meat thermometer.