Programs about food and cooking have been on the air since radio’s earliest days. But The Food Show With Tom Fitzmorris is an anomaly, occupying more hours of prime airtime every week than any other show about taste in the history of the medium. It’s the longest-running talk show of any kind in New Orleans. Twenty-five years, three hours every weekday, same station, same host, same food-and-drink-only concept. The main ingredient in the Food Show’s recipe is, of course, the New Orleans food culture.