An Iron Chef is a story or art challenge that specifies certain specifics, 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.

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. Michelle Klein-Hass is credited with making the Italic textDariaItalic text fan community aware of this show, with Peter Guerin among its biggest fans.