The T-bone is steak of beef cut from the short loin or the sirloin. The steak includes a “T”-shaped lumbar vertebra with sections of abdominal internal oblique muscle on each side. Short loin includes more tenderloin steak, along with a large strip steak. T-bone steaks are cut closer to the front, and contain a smaller section of tenderloin.
The smaller portion of a T-bone, when sold alone, is known as a filet mignon, especially if cut from the small forward end of the tenderloin. T-bone steaks are generally considered one of the highest quality steaks, and prices at steakhouses are accordingly high.