In the US, skirt is the chosen meat for fajitas; itโs actually difficult to get because there are only 4 skirt steaks on a cow, and the restaurants get first dibs on the skirt and buy up almost all of it. Flank is leaner and is the substitute for skirt that most people buy to use for fajitas and other dishes. They are both good, but the flank can be a little tougher.