Kohlrabi is one of those cool vegetables that suffers from not having a well-understood best use-case -- or even a best cuisine that uses it a lot. But this soup looks like a winner to me! Perfect for winter.

Kohlrabi looks like a broccoli with a very big stem:

That soup looks delicious!

Kohlrabi basically IS broccoli stem, according to Wikipedia:

Kohlrabi has been created by artificial selection for lateral meristem growth (a swollen, nearly spherical shape); its origin in nature is the same as that of cabbage, broccoli, cauliflower, kale, collard greens, and Brussels sprouts: they are all bred from, and are the same species as, the wild cabbage plant (Brassica oleracea).

What a wonderful family of vegetables: The cabbages!