Interestingly it was as a guest at Baltimore's Maryland Club that I first encountered cream of kohlrabi soup and loved it. Although basic instincts suggested that the Maryland Club recipe, however delicious, was quite simple, I decided first to check out a few cookbooks for some ideas, if not a recipe promising to be similar. They included Joy of Cooking, James Peterson's Vegetables, Annie Somerville's Fields of Greens, Bernard Clayton Jr.'s The Complete Book of Soups and Stews, and a host of others. Cream of kohlrabi soup was not in any of them.
Nor did much turn up on the Web. The best I could do was "Kohlrabi Thick Soup" from a translated Russian site called "Million Menu." The list of ingredients and extremely brief instructions did convince me, however, that with a bit of tweaking and adaptation, something close to the Maryland Club version was possible.
Kohlrabi, which is particularly popular in Hungary, Germany, Russia, Israel, and China, is very inexpensive and available from time to time in Baltimore, particularly in the fall. I was able to purchase three large heads----easily enough to make soup for sixteen---for just a dollar at the Sunday downtown Baltimore farmers market. To me Kohlrabi tastes like a cross between cabbage and turnip. In Uncommon Fruits and Vegetables: A Common Sense Guide, Elizabeth Schneider, after noting that kohlrabi was "not one of James Beard's favorites," describes it as tasting "like broccoli stems with a hint of radish and turnip---certainly worth a try or two." Interestingly, she includes a recipe for "Hungarian kohlrabi soup," crediting Bert Green's Greene's Green on Green cookbook. It reads like a winner though no dairy products, much less cream, figure into it.
Inspired by the the Maryland Club version and influenced by the instructions given on the Russian site, I took to the kitchen and produced wonderful results.
CREAM OF KOHLRABI SOUP
1 "head" of kohlrabi, including leaves
4 cups canned chicken broth
3 medium to large potatoes
4 tablespoons chopped spring onion
5 tablespoons white wine
1 cup heavy cream
salt and pepper
Chop the leaves after stripping away and discarding the stem part. Peel the kohlrabi "head" and the potatoes with a potato peeler before hand chopping them. Heat the butter in a Dutch oven, add all the vegetables and fry until they begin to soften, but not ready to begin turning brown. Add the chicken broth, cover and cook at a low boil for 10 minutes. Season with salt and pepper. Add wine. In batches, blend all to a puree in a food processor or blender. Add cream, reheat, and serve.