It's always a challenge to figure out creative ways to use kohlrabi. But there are limits. I found this tasty treat in the Croatia section of Yugoslav Cookbook. I'm not going to make it any time soon (or, more accurately, ever, because, well, eew). If you do, let me know how it works out for you.
Here's an enthusiastic diner from page 127, where the recipe can be found. For your delectation, I replicate it here verbatim:
"Kohlrabi stuffed with brains
8 young kohlrabis
14 oz. Calves' brains
1 small onion
2/3 c butter
1c sour cream
Peel the kohlrabies, carefully hollow out the center to make a cup. Place them in a saucepan, cover with cold water, add salt, and cook. Drain well. Remove arteries and membranes, from the calves' brains, wash and cut into small pieces. Chop onion finely and sauté in butter with the brains. Remove from fire. Add salt, pepper, chopped parsley and egg. Mix well. Stuff the kohlrabies with this filling. Place them in an ovenproof dish. Dilute the sour cream with a little water and pour over each kohlrabi, top them with a small piece of butter and bake in oven, 350 F, for 20-30 minutes. Serve hot."
From Yugoslav Cookbook, ed. Stanislava Radovanovic. Jugoslavija Press, Beograd 1977.