This section is from the book "Mrs. Rorer's Vegetable Cookery And Meat Substitutes", by Sarah Tyson Rorer. Also available from Amazon: Mrs. Rorer's Vegetable Cookery And Meat Substitutes.......
Kohl-rabi, also called turnip cabbage, stores its nourishment just above the ground in a turnip-like swelling of the stem, from which long narrow leaves spring. It is free from starch and may, therefore, be sliced and eaten raw in the place of radishes. It is slightly more nutritious than the common white turnip.
Remove the leaves and cut a thick paring from the outside of a dozen kohl-rabi. Cut the flesh into slices of half an inch, throw into boiling salted water, and boil in an uncovered vessel for thirty minutes; drain; turn into a heated vegetable dish and pour over either sauce Hollandaise, white sauce, or butter glaze.