300 g (11 oz) good quality dark chocolate (70% cocoa solids)
1 1/5 l (2 pints) whipping cream
1 tablespoon Cointreau
Zest from 1 orange
Whip the egg whites and caster sugar until it turns into a stiff, white foam.
Mix the hazelnuts in a blender and stir them into the meringue.
Measure up 3 equally large circles on a greaseproof paper.
Pipe or spread out the meringue in the circles and bake until crispy in 150°C/300°F/gas 2 for about 50 minutes. They can be left in the oven in the remaining heat to dry.
Temper the chocolate: melt 100 g (4 oz) of chocolate in a water bath. Remove from the heat and stir in 200 g (7 oz) of finely chopped chocolate in the melted chocolate. Leave to cool and spread the chocolate in the shape of long, oval tongues on a greaseproof paper with the help of a spatula. Leave to set.
Whip the cream and pour in the Cointreau and orange zest.
Put the gateau together; spread a layer of cream between all of the meringue layers and also on top of the gateau. Pipe the remaining cream in dollops all over the top of the gateau.
Put the thin chocolate biscuits around the gateau and stick some of the in the cream on top.