Peel kohlrabis and boil slowly in salted water. When they are semi soft, take them out and let cool off.
Clean root crop, cut in in small pieces and brown on hot oil together with lentils. Baste with stock, cover and stew on very low flame under cover.
When lentils are al dente, remove pan from flame and let cool off a bit. Then add yolk, cheese and cream and stir. Season with salt, pepepr and caraway.
Gouge kohlrabis and fill them with lentil mixture. Stand them in dripping pan lined with baking sheet and bake at 180 °C for 30 minutes. Mix yoghurt with cream. Season dip with chopped herbs, salt, pepper and serve to kohlrabis.