Coming-of-Age
If you can stop thinking about food while reading this book, the fact that it's a coming of age tale becomes pretty clear. After all, Hassan goes from a kid following his nose to a man following his heart (albeit still in the kitchen), and one of his main struggles is figuring out how to make his own way through the world, both in and out of kitchens. Even the title references how much this book is about his personal growth—one hundred feet isn't physically far to go, but it references a life-changing shift in our main man's life.
Coming of age novels often stop once the main character reaches adulthood, which isn't the case with this one. In a twist on the genre, instead we get to see Hassan continue to grapple with coming into his own long after he technically becomes a grown-up. And the thing about this, of course, is that this is pretty much true in life in general. Age is just a number, and figuring out who we are and how we want our lives to be is usually an on-going process.