How to cook
For the layer, knead a dough from the butter, salt, sugar, egg yolks, flour and lemon juice. Roll it out to the size of the tray in which you intend to bake.
Smear the tray with butter, sprinkle with flour and bake the cake until it is semi-ready.
Wait a little for it to cool and smear it with the cream. Put it back in the oven and finish baking.
To make the cream: Mix the egg yolks, sugar, ground walnuts and chocolate.
Heat them on the stove until you get a homogenous, thick cream.