Skirt steaks are boneless and prized for their flavor. In fact, the cut is so rich and flavorful, it has been described as "butter in meat form." It comes from the diaphragm, so it is a muscle that gets used with every breadth the animal takes. It this constant use that gives the skirt steak its tremendous flavor, but heavily used muscles are typically less tender. So, what is the best use of a skirt steak? It is the steak of choice for Philly Steak, fajitas or stir frying because in all in these uses, it it is cut across the grain into thin strips that are inherently tender. If not cut into strips, it benefits from marinating to improve tenderness, and after 24 hours of an acidic marinade, skirt steak can be served whole as it is in Arrachera steaks, a popular Mexican dish.