For raspberry coulis: Place raspberries in a saucepan with water and sugar and bring to boil over a low heat. Cook for 5 minutes and blend. Sieve to remove any seeds. For pistachio brittle: Toast pistachio granules in a non-stick pan over a medium heat, tossing frequently so that they brown evenly. While continuing to toss pan, sprinkle in sugar until it melts and coats the pistachio granules.

Pour granules onto a surface, trying to separate all the pieces of pistachio. Let cool and keep in a warm, dry place. For chocolate mousse: Melt chocolate in a bain marie pan and heat to 90°F. Whip cream with icing sugar until firm. When chocolate has cooled, add to whipped cream in two stages. Put mixture in a pastry bag, close and refrigerate. To assemble dish: assemble dish in big, clear glasses if possible. Alternate layers of chocolate mousse with pistachios and raspberry coulis. Decorate mousse with whole raspberries and a sprig of mint.