Kohlrabi bulbs are surrounded by two distinct fibrous layers that do not soften when cooked. These layers are generally peeled away prior to cooking or serving raw.
The bulbous kohlrabi stem is frequently used raw in salad or slaws. It has a texture similar to that of a broccoli stem, but with a flavor that is sweeter and less vegetal.
Kohlrabi leaves are edible and can be used similarly to collard greens and kale, but take longer to cook.