Wash the potatoes and cook covered for about 20 minutes. Quench, peel and let cool
Clean the chanterelles, wash them if necessary and cut them smaller depending on their size. Peel and finely chop the onion. Wash the thyme, remove the leaves
Dab the fillet dry. Heat the oil in a large pan. Fry the fillet in it for about 5 minutes until it is well done. Season with salt and pepper, remove
Heat 1-2 tablespoons of butter in the frying fat. Sauté onion in it until transparent. Add chanterelles and fry for about 5 minutes. Season with salt, pepper and thyme. Dust with flour and sauté briefly. Stir in about 300 ml water, cream and stock. Bring to the boil and simmer for about 5 minutes. Season to taste with salt and pepper
Dice the potatoes and place them as a wreath on a greased ovenproof deep dish or in a flat casserole dish. Cut the fillet open and place it in the middle. Pour cream of mushroom on top
If necessary, remove the crusts from the toast and crumble finely. Fry in 2 tbsp. hot butter until golden brown. Spread on the mushrooms. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/gas: level 3) for 20-25 minutes
Drink: cool white wine