Cook the peeled kohlrabi cut into sticks in salted water until al dente for about 8 - 15 minutes, depending on the thickness of the sticks.
When draining the kohlrabi, collect a cup of cooking water and let it cool in the refrigerator.
For the sauce, melt the butter, then add the flour, stirring well so that there are no lumps. Add the cold kohlrabi water, stirring constantly, then season with salt and pepper.
Tip:
To refine the sauce, freshly chopped parsley and / or cream can be added.