Peel the kohlrabi and cut into thin slices. Heat water in a saucepan and briefly blanch the kohlrabi slices in it.
Meanwhile, heat some garlic oil in a pan. Peel the onion and cut into small cubes. Put the onions in the pan and sauté briefly. Add the minced meat, season and fry well. Stir the sour cream and tomatoes into the minced meat mixture, if necessary add a little milk depending on the consistency.
Now layer in the baking dish. Kohlrabi, minced meat, feta and kohlrabi again etc. End with feta. Put the whole thing in the preheated oven for approx. 10-15 minutes at 180 ° C.