Where it’s from: Skirt steak is a thin, long cut of beef from the diaphragm muscles of the cow. It is also lean and contains a lot of tough fibers.
Flavor and texture: Skirt steak has even more intense beefy flavor than flank steak. It does contain more tough muscles than flank steak, though, so should only be cooked to rare or medium rare for the most tender texture. It should also be cut against the grain when served.
Cooking skirt steak: Skirt steaks take to marinades even better than flank steaks and are best cooked quickly over high heat, although it can also be slow-cooked and braised. Skirt steak is best seared or grilled and makes a great stir-fry meat. It is the classic cut used in fajitas.