Add chocolate and one tablespoon of water to a bowl and place over a double boiler. Let sit until chocolate has melted and then stir together. Set aside to cool for five minutes.

Seperate eggs. Place yolks and whites in two individual bowls. Add a scoop of the melted chocolate to the egg yolks and whisk well to temper.

Pour egg yolk/chocolate mix back into the rest of the melted chocolate and stir well to combine.

Whisk egg whites until still peaks. Add to the chocolate custard and fold through gently. Scoop mousse into one large serving bowl, or four individual bowls, cover and refrigerate for at least two hours, ideally overnight. Serve as is, or with a dollop of whipped cream on top, berries and grated dark chocolate.