Pittsburgh rare
A Pittsburgh rare steak (or as the locals call it, "Pittsburgh black") is one that has been heated to a very high temperature very quickly, so it is charred on the outside but still rare or raw on the inside. The degree of rareness and the amount of charring on the outside may vary according to taste. The term "Pittsburgh rare" is used in some parts of the American midwest and eastern seaboard, but similar methods of sear cooking are known by different terms elsewhere, including Chicago-style rare and, in Pittsburgh itself, black and blue. One story says that a local slaughterhouse during the depression was looking to make extra money and opened a restaurant in the front. Wealthy socialites could choose their cut of meat off of a live cow and wait while it was slaughtered. The steak would then be seared to kill bacteria and served at the cows body temperature, thus creating "Pittsburgh Rare".
Origin of the term
The term started in the various steel mills in and around Pittsburgh. The mill workers needed high calorie food for the heavy work and had only 30 minutes for lunch. The blast furnaces were heated to over 2,000F degrees. They would throw a steak on the side of the blast furnace which was sterile due to the high heat, leave it for a few moments, and then turn it. The steak was seared but raw inside.
One story relates that the method originated as an explanation for an accidental charring of a steak at a Pittsburgh restaurant, with the cook explaining that this was "Pittsburgh style".
It has been said that the "original" method of preparation was by searing the meat with a welding torch. Whether this is true is unknown . Another method, related by a staff member at a Pittsburgh branch of Ruth's Chris Steak House, originates from the region's steel mills and the practice of workers cooking a steak on a cooling piece of steel. The temperature of the steel would be such that it would be impossible to do more than char the outside of the steak while keeping anything worth eating. One popular version of this myth is that steel workers would bring raw steaks to work and on their lunch break throw them against the huge searing-hot molten steel "tubs". The steak would burn almost immediately then fall off, then they'd throw it up against the other side of the steak. Whether any of these origins is genuine or just a play on Pittsburgh's industrial image is debatable.
Current Usage
Many restaurant guests use the term Pittsburgh to describe a steak that is extra charred on the outside, no matter what internal temperature is desired.