Dab meat dry, wrap tightly in foil and freeze for at least 3 hours. Soak mushrooms in approx. 4 tbsp. lukewarm water
Peel and finely dice the shallots. Heat 1 tablespoon of oil and sauté the shallots for about 3 minutes until translucent. Pour the mushrooms into a sieve and collect the soaking liquid. Squeeze the mushrooms and chop them finely. Add mushrooms and sugar to the shallots and deglaze with balsamic vinegar and 4 tbsp. water. Bring to the boil and simmer for approx. 3 minutes
Clean and clean the mushrooms and cut them into very thin slices. Wash the chives, shake dry and cut into small rolls. For the sauce, mix egg yolk, mustard and wine vinegar. Add 200 ml oil drop by drop while stirring. Season with salt and pepper. Stir in 3 tablespoons of mushroom soaking water. Pour the sauce into a piping bag. Chop the parmesan into fine shavings
Remove meat from the freezer and cut it into very thin slices with a sharp electric slicer or a very sharp knife. Use the rest of the meat for other purposes
Arrange meat on plates. Drizzle with prepared mushroom sauce, sprinkle with mushrooms, parmesan and chives. Add half the mayonnaise. Use the rest of the mayonnaise for other purposes
waiting time approx. 2 1/2 hours
Picture 02-04: Spread mayonnaise in strips over the carpaccio