Boil the eggs for 10 minutes. Cut the kohlrabi into large cubes and cook in 3/4 l boiling water for 7-10 minutes. Drain and collect the cooking water. Measure out 1/2 l vegetable water.
Heat the butter in a saucepan, sweat the flour in it, deglaze with 1/2 liter of vegetable water and the milk while stirring. Season the sauce with salt, pepper and nutmeg. Put the kohlrabi in the sauce. Cut the eggs into quarters and add to the sauce. Let it steep over a low heat.
Dice the Leberkäse and fry in oil, then add to the sauce. Serve with boiled potatoes or mashed potatoes.