Kohlrabi is in the turnip family and has a broccoli/celery-root like flavor. Peel, dice, and either pan-saute in olive oil until crisp or roast to caramelize the edges. Kohlrabi is so crisp and juicy it's well-suited to slicing raw for crudites and salads. It's also delicious stir-fried in strips and can be simmered in soups or mashed like turnips. The collard-looking leaves are also edible - pull them upward off the stem and braise or boil until soft.