Choco holic fix

I am a proud choco-holic and thankfully so is my good mate
he's off in the wilds at present and I am trying not to over indulge but I had a little bar of dark choccie in the fridge and could have simply scoffed it but I decided to go luxe!
the beauty of this recipe is you can make as little or as much as you want

Elizabeth David’s Chocolate Mousse

Makes 1
1 medium eggs
30g chocolate (at least 70% cocoa)
1 tsp sugar (or to taste I used only a pinch)
1. Break the chocolate into pieces and put in a bowl over, but not touching, a pan of simmering water. When the chocolate begins to melt, turn the heat off. Separate the egg.
2. Whisk the egg white into soft peaks, add the sugar, and whisk briefly.
3. Mix the egg yolk quickly into the melted chocolate and then whisk in a third of the egg white. Fold the rest very gently into the mixture until just combined (be careful not to overmix), and then put into a bowl and refrigerate for at least four hours until set.