Combine all of the marinade ingredients in a large flat baking dish or in a large Ziploc bag.
Add the meat and toss in the marinade. For a quick marinade, stab the meat using a fork or a paring knife to allow the seasoning to penetrate the steak.
For outdoor grilling: Preheat your BBQ for at least 10 minutes on high heat; grill for 4 minutes on each side.
For indoor grilling: Heat a grill pan/heavy duty pan on high heat for 2 minutes. Lower heat to medium high, then cook the meat for 4-6 minutes on each side.
Allow the meat to rest on a plate or cutting board for 5 minutes, then slice the meat thinly against the grain. Serve over a salad or in a sandwich.
Recipe by Between Carpools at https://betweencarpools.com/chimichurri-skirt-steak-is-a-bbq-hit/