Flat iron steak is a relatively thick cut, so it should be flipped at least two to three times during cooking. This will ensure that both sides cook evenly and reach the desired texture and temperature. If possible, use a meat thermometer to check for doneness as well. The internal temperature of flat iron steak should reach 145°F (63°C) for medium-rare and 160°F (71°C) for medium-well. Cooked properly, flat iron steak can be a delicious addition to any meal! Enjoy!