I loved the big metaphor of this film
It was easy to see. Just replace every mention of "making food" with "film-making".
A man gets tired of making movies for hire, forced to abandon creativity in favour of giving his audience repetitive and safe choices that the audience grows to mock him for. So what does he do? He goes on the road with a very modest plan, returning to indie filmmaking which gives him newfound success and allows him to make movies that he cares about.
And the best part was that I wasn't even describing the synopsis of "Chef"'s plot, I was describing how Jon Favreau ended up making "Chef".