A porterhouse steak is a large, thick cut of beef taken from the rear end of the short loin.
Although it is not linked to a specific country of origin, it is most commonly associated with British and American cuisines. It is named "porterhouse" because it was traditionally served in 18th-century porterhouses, which were inns or restaurants that served porter beer.
The defining characteristic of a porterhouse steak is the T-shaped bone that runs through the center, separating two different cuts of meat: the strip steak (commonly known as the New York strip - marbled, flavorful cut known for its beefy taste) and the tenderloin (also known as filet mignon - tender and lean cut, prized for its mild flavor).
A properly cooked porterhouse steak will have a juicy and tender texture with a combination of flavors from both the strip steak and the tenderloin. Due to its large size, it is often considered a steak for sharing or for those with hearty appetites.