Poor kohlrabi. I almost never see it for sale, and when I do find it, I am invariably asked by a fellow shopper: "what the heck is that?"
Technically, a kohlrabi "bulb" is the swollen stem of the kohlrabi plant. It tastes like a cross between broccoli stems and turnips. If you are very fortunate, you can find kohlrabi with the leaves still attached: they are great sauteed with garlic and oil.
Prep is relatively easy: just peel the tough skin off with a vegetable peeler. The older the vegetable, the thicker the skin - try to buy smaller ones if you can.
Kohlrabi is very poorly represented in my cookbook collection. I looked and looked and found recipes in Jack Bishop's Vegetables Every Day and the Silver Palate ladies' The New Basics. Mark Bittman's How to Cook Everything (ahem) let me down (he copped out by mentioning kohlrabi, but then sent me to the turnip section).
I ended up by following Bishop's recommendation and cut these into chunks and then roasted them in the oven (at about 400) until brown and tender. They were a savory side dish for a cool evening's meal.
A Silver Palate suggestion which I want to try suggested shredding it and making kohlrabi pancakes. That was a tempting idea, but too much work for tonight.
How do you cook your kohlrabi?