Rub the fillet with salt and pepper. Heat 10 g clarified butter in a pan and fry the fillet all around. Continue frying over a low heat for about 10 minutes. Clean the oyster mushrooms and rub carefully with kitchen paper.
Clean, wash and thinly slice the zucchini. Heat the rest of the clarified butter and sauté the vegetables and 3 tablespoons of water in it over low heat for about 5 minutes, turning several times.
Season with salt and pepper. Peel and finely dice the shallot. Remove the meat, wrap in aluminium foil and keep warm. Sauté the diced shallots in the cooking fat and deglaze with cognac and cream.
Let it thicken a little. Add green pepper. Season to taste with a little salt. Stir in the sauce thickener and let it boil up briefly. Cut the meat open and arrange on a preheated plate with the vegetables and sauce.
Garnish with parsley. Baguette tastes good with it.