Peel onion and chop finely. Heat the fat in a saucepan and sauté the onion cubes until translucent. Deglaze with cream. Let the liquid boil down for 5-10 minutes.
Clean and wash the pointed cabbage, cut out the stalk and cut the cabbage into strips approx. 1 cm wide. Then put in boiling salted water and blanch for about 5 minutes. Then drain well.
Whisk some cream and onion sauce with egg yolk and stir into the sauce that is no longer boiling. Season with salt and pepper. Fold in the pointed cabbage.
Tip: If you want to save calories, you can of course swap the cream for low-fat milk.