I have a certain fondness for kohlrabi and was delighted to see this big bunch of it for only $1.70 at Wegmans. I tried growing this last year, but for some reason, they never got big enough to eat.
It is at times difficult to find in stores, but lately I have been seeing some really fresh bunches in the stores even though the official season isn't until late Summer. Both the greens and the "bulb" (it is generally called that even though it is not a bulb and grows above ground) are edible, you can cook the greens the way you would mustard greens or chard and the peeled bulb can be eaten raw or roasted or boiled.
It is hard to describe the taste of a kohlrabi. It almost tastes like the peeled stem of a crown of broccoli but milder. The texture is similar to that of a crisp apple, but it is not sweet at all.