Peel and wash the potatoes and slice them into thin slices. Grease 4 gratin dishes (approx. 200 ml content) with some truffle butter. Layer the potatoes like roof tiles, season with salt and pepper.
Warm the cream, melt the remaining truffle butter in it. Pour over the potatoes. Bake in the preheated oven (electric cooker: 200°C/circulating air: 175°C/gas: level 3) for approx. 45 minutes until golden brown.
Cook the shallots in boiling water for 1-2 minutes. Quench and peel. Then fry in 1 tbsp. hot clarified butter. Season with pepper. Sprinkle with sugar and caramelise until golden. Deglaze with stock, bring to the boil and simmer for about 5 minutes.
Wash the rosemary and shake dry.
Pat the steaks dry and tie 1 sprig of rosemary around each. Fry the steaks in 2 tablespoons of hot clarified butter for about 3 minutes on each side. Season with salt and pepper, keep warm. Add balsamic vinegar to the meat.
Add shallots, simmer briefly and season to taste. Serve everything. Add the Romanesco.
Drink: red wine, e.g. 2007 Mönch Berthold red wine cuvée dry, wine manufactory Untertürkheim