Wash the potatoes with skin on, place on baking paper and cook in the oven at 180 degrees Celsius for about 1 hour until they are soft.
Press the hot potatoes through a potato press (alternatively peel and mash). Warm the plant milk together with the vegan butter. Mix in the potatoes. Season the mashed potatoes with salt, pepper and nutmeg.
Wash the apples, remove the core and cut into approximately 1 cm thick slices. Sprinkle each apple ring with a pinch of sugar. Caramelize the apple slices in a pan with the vegetable oil on both sides over a medium to high temperature. This takes about 1-2 minutes per side.
Cut the onions into fine slices, mix with the flour and season with salt and pepper. Braise in the same pan at medium temperature with a good dash of vegetable oil for about 5 minutes.
Cover the seitan steaks nicely with the marinade on all sides before frying them. Otherwise add some oil to the pan. Then fry briefly on both sides with high heat and remove.
Then stir in the flour for the sauce in the pan and sauté briefly. Deglaze with 250 ml of stock and let it boil for 1 minute while stirring.