Skirt steaks are a cut of beef from the diaphragm section of the cow. Typical features of this cut include a strong beef flavor and a grainy texture. Cuts of skirt steaks are typically long and thin. When panfrying skirt steaks, choose a cut of beef that is approximately 3/4-inch thick. Cook the skirt steak on the pan only until it reaches medium since well-done skirt steaks have a tough and chewy texture.
Cut the skirt steak in half so it fits well in your skillet and trim off any excess fat with a sharp knife.
Mix the spicy mustard and lemon juice in a small bowl.
Place the steaks in a shallow container and pour the mustard-lemon marinade over the meat. Cover the container with plastic wrap and place it in your refrigerator.
Take the steaks out of the marinade after 1 to 2 hours. Discard any excess marinade.
Heat a cast-iron skillet to medium on your stove, and lightly cover the surface of the pan with canola oil.
Set the skirt steaks into the preheated frying pan. Use a spoon to baste the steaks with the pan juices several times during cooking to help the meat retain its moisture.
Fry the steaks on each side for approximately 3 minutes for medium-rare doneness. Cook for 4 minutes on each side if you want it to reach medium doneness. For medium-rare, the internal temperature taken with a meat thermometer will be between 130 and 135 degrees Fahrenheit. Medium steaks have an internal temperature of 140 to 145.
Remove the skirt steaks from the heat, and set them on serving dish. Allow the meat to rest for at least 5 to 10 minutes before serving