It’s not every category of ingredient that warrants its own cookbook.

For example, you are not likely to buy a cookbook on just onions, because they’re simply too common; you can find an onion family member hiding in the background of most savory dishes. For the opposite reason, you are not likely to find a cookbook on reindeer meat. But some categories are just broad enough and just coherent enough that it’s worthwhile to have a whole book devoted to them. Root vegetables are one such category.