Walnut Rolls

It is necessary:

one egg,
150 g ground nuts,
250 g powdered sugar
60 g chocolate
50 g butter.

Preparation:

Knead the mass of one egg white, 150 g ground walnuts, 150 g of powdered sugar and 60 g of melted chocolate.
Prepared mass stretched on a board covered with sugar in crust thick half an inch.
For the filling, mix 50 g butter, 100 g powdered sugar and one egg yolk boiled and strained.
Coat crust with filling wrap into a roll and leave to cool to have a good set.