How did the iron chefs become iron chefs?

Iron Chef America was originally titled Battle of the Champions, where Bobby Flay, Mario Batalli, Masaharu Morimoto, and the retired Wolfgang Puck were selected to battle each other on the show. However, the three newest Iron Chefs (Cat Cora, Micheal Symon, and Jose Garces) were winners of The Next Iron Chef, and, as the name implies, they became the next Iron Chefs.