Carne asada is traditionally made using skirt steak or flank steak.   Though the cuts are very similar (both are tough, lean cuts of meat), there are a few differences.   Flank steak is a leaner of the two, and is a thicker, wider, and heavier meat cut than skirt steak. It also has a more tightly woven grain structure than skirt steak.   Flank steaks take a few extra minutes to cook in comparison with skirt steak.   Skirt steak has a less dense and more fibrous grain structure. It is a fattier piece of meat than flank steak, and is typically a long skinny and thin cut.    Because it’s less dense, skirt steak reacts well to marinating, and is our recommendation for carne asada if you can get it.   Regardless of which you use, be sure to cut against the grain after grilling.