Start this recipe by preparing the potatoes. Place in a saucepan of water and bring to the boil. Lower the heat and cook the potatoes until soft. Meanwhile you can start preparing the pork. Season the 2 pieces of pork fillet with salt and pepper and seal in a hot pan with the olive oil. Remove from the pan and continue to cook in the oven for 10 minutes. In the same frying pan, melt in the add in the diced mushroom Kabanos and brown for 2 minutes. Next, melt in the butter and soften the onion and garlic together with the sprigs of thyme. Splash in the brandy, evaporate then pour in the cream and reduce. When the potatoes are cooked, drain away from water and crush. Mix in the crushed garlic, olive oil and season well with salt and pepper. Finally, remove the cooked pork fillet from the oven and allow to sit while you quickly pan fry the oyster mushrooms in a clean pan for 2 minutes. To serve, place the crushed potatoes into cutters on your serving plates and remove to create a potato cake. Slice the pork fillet and decoratively arrange the slices around the crushed potato. Finally, place the oyster mushrooms on the potato cake and drizzle the Kabanos cream sauce over the pork slices and around the edge of the plates.