Cleaned trout are arranged close to each other in the baking pan, shaped in the form of the letter "S", add 30 g Heat the butter, add salt, sprinkle with chopped mushrooms into thin pieces , capers, lemon zest and lemon juice. Tray covered with foil and bake in oven for 30-40 minutes weak. Meanwhile makes light roux of 30 g the butter and flour, gradually diluted with milk and boiled, add the mushrooms, capers, sauce from baking trout, add salt and heat. The potatoes are cooked, well creased or compressed, added 1 tbsp (10 ml) of milk, 30 g butter, pepper and salt, the mixture was stirred and extruded sprockets along the circumference of the oval, the preheated plate. In the middle are arranged trout, decorate with sterilized onions and serve. The sauce is served separately.