Looking something like a Sputnik in vegetable form, with a squat bulb and antennae-like shoots, kohlrabi is part of the cabbage family. The name translates as 'turnip cabbage' and the mild, sweet flavour is somewhere between a turnip and a waterchestnut, with a crisp, crunchy texture. It can be found in two colours, pale green and the less common purple.
Snip off the leaf stems, trim off the base and top, then use a potato peeler or sharp knife to peel it as if it's an apple. Then thinly slice, chunk or cut into wedges. If you're using slices in a salad, blanch them first.
Trim off the stems and keep in a perforated bag in the fridge - it will last up to two weeks.
To roast, steam the bulb for 5 minutes, then roast for 45 minutes. Steam (up to 12 minutes). Stir fry (up to 6 minutes). The leaves can be cooked like cabbage.