Preheat the oven to 210 °C. Preheat deep fryer to 180 °C.
Peel the floury potatoes and cut into equal sized pieces. Cook in boiling water with a boiling pinch of salt for about approx. 20 minutes until tender. Drainthe potatoes. Heat the milk with 75 g of butter. Add to the potatoes and roughly mash. Season with salt and pepper.
Meanwhile, place the baby patty pans in an ovenproof dish. Sprinkle with olive oil and season with salt and pepper. Place in the middle of the oven and bake for approx. 12 minutes until they are soft and cooked. Divide the nuts over a baking tray. Roast for about 8 minutes at the bottom of the oven, underneath the patty pans, until the nuts are golden brown. Leave the nuts to cool slightly, then chop roughly.
Thinly slice the truffle potato. Pat the slices dry with kitchen paper. Fry in the deep fryer for approx. 3 minutes until crispy. Drain the truffle potato crisps on kitchen paper.
Pat the tournedos dry with kitchen paper and season with salt and pepper. Heat 2 tablespoons of butter in a large frying pan . Fry the tournedos on a high heat for about 5 minutes until brown. Turn them halfway. Remove the tournedos from the pan and let them rest covered for 5 minutes.