Stir in the cooled chocolate and then the chestnut puree, brandy. Mix until smooth. Pack the mixture into the tin, cover and chill for at least 12 hours or even upto a week. To serve, unmould the pave and discard the paper. Cut the pave in thin slices with a knife dipped in hot water. Set the slices on your plates and decorate with chantilly cream, using a piping bag and star tube. Chill until ready to serve.