An Iron Chef is a story or art challenge that specifies certain things that must be included, such as subject matter, character used, or story length. Most commonly, these are open to all interested parties. In some cases, "I Challenge You" invitations may be offered that specifies a particular writer or artist to attempt the task, with the understanding that the challenged is free to decline without prejudice. Iron Chefs were first seen in Daria fandom on PPMB and spread to SFMB thereafter. (See Leather Chef.)
The term is derived from the popular cooking show originally shown on Japan's Fuji Television Network from 1993-1999 and later presented on the US cable channel Food Network.