In a bowl, prepare the marinade by joining the bean purée, sugar, coarse salt and water. Use a spatula to stir.

In single-portion mold, add a layer of marinade, then the egg yolk, and then another layer of marinade.

Let marinade for 6 hours, being careful to turn over the yolk at the halfway point in order to ensure an even cooking. After 6 hours, rinse the yolks carefully under running water.

Spread them out between two sheets of waxed paper until obtaining a single sheet less than 1 cm thick. Pass it through a pasta machine set for tagliolini. Now shape little nests out of the tagliolini, each weighing about 15 g.

Place them on the serving dish and cook in a 950 Watt microwave for 35 seconds. Let cool and garnish with thin shreds of the dehydrated truffle.