Combine the garlic, herbs, oil, and lemon juice in a large zipper bag.
Rinse the steak, pat it dry, and transfer it to the bag with the marinade.
Seal the bag, move the contents around to coat the meat evenly, and refrigerate for 2 hours.
Meanwhile, combine the dry seasonings in a bowl to make the rub.
Remove the steak from the marinade and allow it to return to room temperature.
Preheat your Z Grills (preferably with branded wood pellets) or other wood pellet grill to 225 degrees Fahrenheit.
Pat the skirt steak dry and apply the dry rub to both sides.
Transfer the steak to the grates, close the lid, and smoke for 45 minutes to an hour.
Remove the steak from the grill, increase the grill temperature to 450 degrees Fahrenheit, return the steak to the grates, and cook for 2-3 minutes per side to sear.
Remove the smoked skirt steak from the grill and rest on a cutting board for 10 minutes.
Slice against the grain at a 45-degree angle and serve.