Preheat the oven to 140 °C.
Season the pork fish with salt and pepper and sear it in a frying pan in hot clarified butter on all sides. Then cook in the heated oven for fifteen minutes. Then remove the meat and brush it all over with mustard.
Mix the freshly chopped parsley with the breadcrumbs and then roll the pork fish in it.
Fry the bacon and onion cubes and the thyme leaves in a large frying pan with a little clarified butter.
Cut the potatoes in a special vegetable slicer to long spaghetti – or with a kitchen knife into fine strips – and on the bacon and onion mixture form, press evenly and roast leisurely until golden brown.
Season the rösti with salt and pepper and then place on a dish hangl form. Put the pork fish on it and roll it up carefully with the help of a cloth. It is important that the Rösti is well pressed. Place the wrapped fillet on a tray rubbed with clarified butter and cook in the heated oven for ten minutes.
In the meantime, cook the mushroom cream sauce: fry the mushrooms, shallots and garlic in clarified butter, remove and drain. Pour half of the whipping cream and chicken stock into the frying pan and cook until creamy. Season with salt, pepper and a pinch of nutmeg and add the fried mushrooms, garlic and shallots. Whip the remaining whipping cream until stiff and add to the