Wash the pork schnitzel and pat dry. Season with salt and white pepper and place side by side in a baking dish.
Cut the mushrooms into slightly thicker slices. Cut the onions into strips and fry them in a pan with the mushrooms in a little oil. Add the cream and sour cream and bring the sauce to the boil, season with salt, black pepper, both types of paprika, vegetable stock, thyme and cayenne pepper and simmer for about a minute.
Spread the mushroom sauce on the schnitzel, sprinkle the parmesan on top and put everything in the oven for 20-25 minutes.