That alien spaceship looking thing. Well, its actually delicious and versatile. The taste is somewhat similar to cabbage and broccoli with the crunch of a radish and the crispness of a cucumber.
Store all parts in the crisper. Leaves will keep longer if removed and stored in a plastic bag similar to other greens. The bulb will keep up to a month in the fridge.
The trick to enjoying you kohlrabi is to peel or actually par the skin and the green layer after the skin until its all white if eating raw. Otherwise just the skin works if roasting, grilling or stewing. The leaves are also great stewed or roasted.