Kohlrabi (pronounced “cole-rah-bee”) is actually a cabbage, selectively bred by farmers over 500 years ago for its thick stem. Use kohlrabi cooked as well as raw. Edible preparations are made with both the stem and the leaves. The texture and taste of kohlrabi are comparable to those of a broccoli stem or cabbage heart, but sweeter and milder, with a higher ratio of flesh to skin. The young stem, in particular, can be as crisp and juicy as an apple, although much less sweet.
Read more here: Five Ways to Use Kohlrabi