Known for its deep beefy flavor and open-grained texture, inside skirt steak is a thin, richly flavored cut that takes especially well to marinades and high-heat cooking. This 2.5-pound piece comes from grass-fed Black Angus cattle raised in New Zealand. Its relatively loose muscle fibers absorb seasonings readily, while quick cooking develops a well-browned exterior without sacrificing the meat’s juicy texture.
Inside skirt comes from the abdominal wall, while outside skirt is cut from the diaphragm. Outside skirt is generally thicker, more uniform, and naturally more tender, while inside skirt tends to be thinner, wider, and slightly chewier. Both offer the pronounced beef flavor for which skirt steak is prized, but inside skirt rewards careful preparation: trim away any excess surface membrane, marinate if desired, and cook it quickly over very high heat. A hot grill, cast-iron skillet, or broiler works best. Cook only to medium-rare or medium, let the steak rest, then slice it thinly against the clearly visible grain for the most tender bite.
Skirt steak is the classic cut for beef fajitas, and this inside skirt is particularly well suited to the dish because its open texture readily takes on marinades of lime, garlic, chiles, and spices. It can also be grilled and served with chimichurri, tucked into tacos, layered into steak sandwiches, added to salads or rice bowls, or sliced alongside roasted vegetables. For easier handling, cut the large piece into shorter sections before cooking, noting the direction of the grain so each section can be sliced across it before serving.