Clean and wash the cabbage. Peel, wash and cut the potatoes into pieces. Both in
Covered with approx. 3/8 l boiling salted water and cook for approx. 15 minutes. Then drain and collect the vegetable water
Wash the fillets, dab dry. Fry in hot oil for 5-6 minutes on each side. Season with salt and pepper, remove
Peel and finely chop the onion. Heat the fat in the frying fat. Sauté onion in it. Dust with flour and sauté briefly. Stir in 1/4 l vegetable water, milk and stock. Bring to the boil and simmer while stirring for about 5 minutes. Melt cheese in pieces in the sauce over a mild heat. Season to taste with pepper, nutmeg and possibly salt
Place the cabbage and potatoes in a greased ovenproof dish. Cut the fillets into slices and place them on top. Pour sauce over them. Sprinkle with nuts. Gratinate in a preheated oven (electric cooker: 225 °C/circulating air: 200 °C/gas: level 4) for 8-10 minutes