Table: iron_chef_au
Columns: episode
airdate
iron_chef
challenger
theme_ingredient
winner

Question: Who was the challenger when guillaume brahimi was the iron chef?
SQL: SELECT "challenger" FROM iron_chef_au WHERE "iron_chef" = 'Guillaume Brahimi'

Question: Who was the iron chef when herb Faust was the challenger?
SQL: SELECT "iron_chef" FROM iron_chef_au WHERE "challenger" = 'Herb Faust'

Question: What date did the episode air when guy grossi won?
SQL: SELECT "airdate" FROM iron_chef_au WHERE "winner" = 'Guy Grossi'