Sometimes the simplest recipes like chocolate mousse can cause a lot of confusion. Some recipes are as simple as melted chocolate folded into whipped cream. Others use gelatin to set the mousse or whipped egg whites to lighten the mixture. There is no right or wrong way, it just depends what you want to do with it (apart from just eating it) and how much time you have. This recipe is one of my favourites because it's decadent, smooth and chocolatey without being too sickly sweet. I memorize how to make it by remembering three steps... make an anglaise, add chocolate and whip with cream. Voila!
If you find the mousse isn't sweet enough, you can add a little sifted icing sugar to it while you are whipping it up.