Clean and wash the Brussels sprouts. Peel and finely chop the onion. Fry in hot oil. Add cabbage and steam briefly. Deglaze with 200 ml water, bring to the boil. Stir in stock and cook covered for about 10 minutes
Peel, wash and roughly grate the potatoes. Fill the Brussels sprouts and broth into an ovenproof dish. Spread the grated potatoes over it. Season cream with salt, pepper and nutmeg. Pour evenly over the cabbage
Bake the casserole in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/gas: level 3) for 40-45 minutes. Remove and garnish with nut flakes and marjoram as desired