Salt and Pepper both sides of the skirt steak.
Mix all of the rub ingredients together in a small bowl.
Rub the rub mixture onto each side of the meat. Place in container, cover, and let the meat marinate for at least an hour. (I usually let the meat marinate overnight).
When ready to cook the meat, remove meat from refrigerator (if marinating overnight). Let the meat come to slight room temperature to allow even cooking. (For at least 15 to 20 minutes. You can let it sit out while you prep the grill.)
Prep your grill. Once the charcoals are gray, and the grill is hot, place the steaks on the grill, close the cover.
For a medium rare steak, cook the steak for 4 to 6 minutes per each side.
Remove the steak from the grill, cover the plate/pan of steaks loosely with foil. Let the steaks rests for a few minutes to allow the juices of the meat to redistribute back into the steak, to ensure the steaks are juicy.
While the steaks rest, mix the Chimichurri Sauce ingredients together, set aside.
Cut the steaks into thin slices, make sure to cut against the grain when slicing the steaks.
Garnish the sliced steak with the Chimichurri Sauce, and serve immediately.