A simple answer to your conundrum could be how he manages his cadence and deals with pressure. Programming isn't especially difficult in my opinion. In many cases, sheer throughput seems to have a lot more to do with success than raw talent. Someone who was previously a chef might have a huge advantage in this regard, since working in a kitchen is a really demanding occupation. He probably has excellent training in dealing with pressure and time constraints. Perhaps being a programmer is even a relief compared to being a chef!