The skirt steak is located near the plate, and is actually the diaphragm of the steer or heifer. This muscle helps the animal breath, and because of the pasture-raised lifestyle they lead, this muscle gets an incredible workout, which creates an awesome flavor and large muscle fibers.
This thin cut only needs to be cooked over high heat for a very short period of time, 3-5 minutes per side. After you let the meat rest, slice the skirt into thirds, lengthwise. This will make it easier to slice against the grain, which runs from top to bottom on the short side of the meat.