Prepare the marinade. Combine all of the ingredients in a gallon zip top bag and really massage to combine. The massage also releases the oils from the cilantro, onion, and garlic into the liquid.
¼ cup avocado oil, 2 Tablespoons Hey Grill Hey Fiesta Rub, 2 Tablespoons fresh lime juice, ½ cup fresh cilantro leaves, ½ white onion, 4 cloves garlic
Marinade the steak. Place the skirt steak in the marinade, press out any excess air from the bag and seal. Refrigerate for at least 4 hours, but preferably overnight.
2 pounds skirt steak
Preheat your grill. Heat your grill to high (around 600-650 degrees F).
Grill the steak. Carefully remove the steak from the marinade, shaking off any excess pieces of onion, herbs, or garlic. Place it directly on the grill and cook with the lid up, flipping every 2-3 minutes until a dark crust is developed on the outside and the internal temperature of the steak reads 130 degrees F.
Slice and serve. Remove the steak to a cutting board and slice into thin pieces, against the grain.