Carne asada is typically made with skirt steak.
Skirt steak is a long, fatty cut from the diaphragm, this cut is usually what you're eating in a fajita or in a stir-fry. You'll also find it served up on a skillet and cut against the grain to maximize tenderness.
Skirt steak can be found right along the front of the belly, underneath the rib.
Learn more about other cuts of beef at Thrillist.
Find out How to Make the Best Carne Asada at SeriousEats.
The DinnerPlanner.com shares a simple guide to help choose the right cut of beef for all your beef recipes.