Kohlrabi can be eaten raw or cooked. When eaten raw it has a pleasant turnip flavor with lots of crunch. To eat raw, first peel off the outer layer of skin, and slice thinly or dice and serve on salads.

KOHLRABI AND APPLE SALAD WITH CREAMY MUSTARD DRESSING  (epicurious.com)

1/2 cup heavy cream
2 tablespoons fresh lemon juice
1 tablespoon coarse-grained mustard
3 tablespoons finely chopped fresh parsley leaves
1/2 teaspoon sugar
2 bunches kohlrabi (about 2 pounds), bulbs peeled and cut into julienne strips, stems discarded, and the leaves reserved for another use
1 Granny Smith apple

In a bowl whisk the cream until it holds soft peaks and whisk in the lemon juice, the mustard, the parsley, the sugar, and salt and pepper to taste. Stir in the kohlrabi strips and the apple, peeled, cored, and diced, and combine the salad well.

 BRAISED KOHLRABI (tonytantillo.com)
The assertive flavor of kohlrabi holds up well to spicy preparations.
Makes 8 servings

A good-size bunch kohlrabi with greens attached, about 3 pounds
1 tablespoon vegetable oil
1/2 teaspoon each cumin and yellow mustard seeds
1 tablespoon chopped garlic
1 small jalapeno or other hot pepper, seeded and minced
1/2 cup chicken stock or water
Kosher salt and freshly ground black pepper to taste

Discard any yellow or badly withered greens from the kohlrabi and cut off most of each stem. Stack the leaves, then roll them in cigar-like fashion and cut across into thin strips, 1/4 to 1/2 inch wide. Put greens in a basin of cool water to remove grit. Drain in a colander. Peel and cut kohlrabi into 1/2 inch dice and add to the greens. Put oil in a wok over medium heat. Add cumin and mustard seeds and stir a few seconds until mustard seeds begin to pop. Add garlic and jalapeno and stir a minute or two until garlic turns light golden. Add diced kohlrabi, greens, stock, and salt and black pepper to taste. Toss, cover, and reduce heat to medium-low. Cook, tossing once or twice, about 20 to 25 minutes or until kohlrabi is tender. Add a bit more liquid if needed.