A French classic dessert with no cream: a light yet intensely bittersweet dark chocolate mousse for serious chocolate lovers who love their chocolate rich and airy.
Melt the chocolate and cocoa powder together in a bowl over a pan of simmering water (Bain-marie), taking care not to overcook the chocolate (don't have the water at a rolling boil, just simmering gently). As soon as the chocolate begins to melt, switch off the heat and stir until completely smooth, then take the bowl off the heat.
Separate the extra egg, keeping the yolk aside for later (it's important the yolk is at room temperature).
In a clean bowl, whisk the egg whites (using a stand mixer or electric beaters) with the sugar until soft and strong peaks form. Add the extra egg white and continue to whisk.
When the whites are strong and hold well, continue to whisk in the egg yolk and add the fleur de sel.
Gradually add the whipped egg whites to the chocolate using a strong yet flexible spatula, folding each carefully until well blended together. Repeat folding gently until the consistency is completely mixed together, light and airy.
Either transfer the bowl to the fridge or pour/spoon into serving glasses and place in the fridge to set for at least 2 hours until ready to serve.
Serve chilled and top with fresh fruit, shaved chocolate or a sprig of mint.
Serve chilled with chocolate macarons (see the recipes in both my books), crispy almond tuiles, or garnish with a sprig of mint, edible flowers or fresh fruit. If you really want the cream, add a dollop of freshly whipped Chantilly cream.
Variations: Omit the salt and add a teaspoon of soluble coffee granules for a mocha treat - or add the zest of an orange or lime for a citrus take on the recipe. Add a tablespoon of Cognac or Grand Marnier liqueur for a special occasion (adults only).
Note: see list of egg yolk recipes for the leftover egg whites needed for this recipe.