Preheat the oven to 180°C. Crush the pecan nuts.
Separate the eggs, keeping the yolks separate from the whites. Place the egg yolks, caster sugar and the brown sugar in a bowl. Beat until pale and fluffy. Melt the chocolate over a bain marie. Mix together the flour, cocoa powder and the pecan nuts.
Whisk the egg whites until stiff.
Mix the chocolate into the egg yolk and sugar mixture. Combine well and then add in the flour mixture. Finally, fold in the egg whites.
Spread this mixture on to a silicone baking sheet, transfer to the oven and bake for 15 minutes.
Once cooked, use square shaped serving rings to cut the chocolate base to shape.
Place the gelatine leaves in a bowl of cold water to soften. Heat the cream in a saucepan. Mix together the egg yolks and the sugar, beating until the mixture is pale and fluffy. Add the hot cream to the mixture, return to the heat and cook until the mixture reaches 84°C and coats the back of a spoon. Add the softened gelatine and the pistachio paste.
Use square serving rings to assemble the dessert: the chocolate biscuit forms the base. Pour the pistachio cream on top and then chill in the fridge for at least 1 hour.
Once the pistachio cream has set, remove the serving rings. Top each dessert with griottine cherries and finish with a drizzle of raspberry flavoured balsamic cream.
«If you need to chill the dessert rapidly, feel free to place it in the freezer for 20 minutes and then in the fridge for a further 20.»