Do you mean skirt steak?
A skirt steak is a lesser cut. It is the cow's diaphragm muscle,
and is cut from the flank. It is a long, flat piece of meat, with a
tendency toward toughness. But it has good flavor. It can be
grilled or pan fried quickly with good results. Another traditional
method is to stuff it, roll it, and braise it. The skirt steak is
often used to make fajitas.