Peel turnip cabbage and cut into small stripes. Dice onion. Heat oil and saute onion and turnip cabbage for some minutes. Add beef stock and boil up. Season with salt and pepper. Let all cook covered for about 15 minutes. Dice finely turkey escalope and mash them in a mixer. Stir in yellow of the egg and creme fraiche. Season with salt and pepper. Allow to rest 10 minutes in the refrigerator.
Lift out approximately 200 g of the trunip cabbage stripes. Stir in chervil and blend soup well. Add cream, boil up once and season to taste with salt, pepper and nutmeg. Add cabbage stripes and warm up. Form nut sized dumplings with the turkey puree and let them sit for 3 - 5 minutes in salted water.