Cut the fillet into pieces and soak in lemon pepper and oil for 1-2 days.
Drain the meat, fry it and place in a baking dish. Fry the onions and mushrooms. Add white wine, then slowly stir in the herb cream cheese, cream and herb crème fraiche. Season with salt, pepper and fresh marjoram.
Pour the mixture over the seared meat, sprinkle with grated cheese and bake in the oven at 180 ° C for 20 minutes.