Herzog has something of a track record with this type of bet. When making "Even Dwarves Started Small" he promised his actors that if they all survived the shoot he would jump into a cactus patch for their amusement. They did, so did he, and he claims to still have some spines in his body as a result.
Herzog once promised to eat his shoe if a certain young American film student went out and actually made the film he was always only talking about. The young student was Errol Morris, who met the challenge with his off-beat 1978 pet cemetery documentary Gates of Heaven (1978) (and went on to make The Thin Blue Line (1988) and Fast, Cheap & Out of Control (1997)). Herzog makes good on his promise in this film.
The woman who helps Werner Herzog cook his shoes is the famous chef Alice Waters. The shoes were cooked in the kitchen of her restaurant, Chez Panisse, in Berkeley, California. There are shots in the film of Herzog entering the restaurant wearing his shoes, and leaving it barefoot.