Place the peeled chestnuts in a small pan and cover with milk and allow to simmer until all the milk is absorbed.
Then pass the chestnuts through a mill or ricer into a bowl. Add the melted chocolate and icing sugar, pack into the bowl and leave to chill for at least an hour.
When ready to serve, take the purée and put it through the ricer again letting it fall into the bowls like a mountain (monte). Put a spoonful of whipped cream on top (bianco) and dust with icing sugar “snow”. Note: some people add a little cognac to make it extra special.