This is a pretty liquid mousse - it doesn't set up particularly firmly, which means it looks luscious dolloped onto whatever you want to serve it on/in, and you can plate it up just before serving, which is definitely a plus when fridge space is at a premium and you're serving dessert to 10 people - a lot easier to fit one (or two) big bowls into an overcrowded fridge than 10 pretty glasses or plates!
Melting the chocolate is a tricky thing - I do this in short bursts in the microwave until it's warm enough to melt the remaining solids, but not too hot. You need to let this cool a little before adding the egg as otherwise it will curdle - so the best system is to get all your equipment out, make sure you have enough bowls, measure all your ingredients, then melt the chocolate, which will give it a little time to cool while you prepare the eggs.
The egg whites have to be beaten with the sugar until well combined - easy peasy.
Then you simply mix the yolk mixture into the chocolate - make sure it's well combined and then immediately fold through some cream and egg white. Get this mixture good and smooth (technically you should only fold as soon as you start incorporating the airy bits but I think it's more important to have consistency and will beat some of the air out if I have to to ensure the chocolate is evenly distributed) then alternate folding big blobs of cream and egg white through the mixture until it's all combined.
We made our mousse into little towers (because, according to Black Books, all fancy food should be served in a tower) using brandy snap discs (bought from Moore Wilson's - the lazy way but fabulous when you're doing a bunch of other stuff as well) and berries (from frozen, though we defrosted them first) to make a dessert that was pretty low stress and yet impressively decadent. I'm sorry the photo is so lousy - I was in a hurry to get them on the table - but hopefully you get the idea:
They tasted fantastic (if I do say so myself!).
Amusingly enough, I found this recipe a few years back on this French property website, which has since been redone and the recipe seems to have vanished (somewhat unsurprisingly, since it seemed somewhat irrelevant to house-hunters!). At the time I was seeking an 'authentic' mousse recipe, which is to say, one which doesn't use any setting agents like gelatine. As I mentioned above, this means it is fairly sloppy, but it's perfect for layering with fruit in a glass or doing as we did with our brandy snap discs.
I made a double mixture, and weighed out half the egg whites, yolks and cream before layering them together, and I used Whittaker's 50% dark (which is nice but not too bitter, though you can use whatever you prefer), and their white chocolate, though I don't like their white choc as much as Cadbury Dream.
200g dark chocolate
50g castor sugar
Prepare three large bowls (or pots!). Separate the eggs, yolks in one of these and whites in another, and measure the cream into a third.
Put 200g of chocolate, broken into evenly-sized pieces, into a microwave-proof container and melt by putting in the microwave for short bursts. Once the chocolate is mostly melted stop heating it and stir until smooth.
Mix the sugar into the egg yolks until combined. Beat the cream until thick but not stiff. Beat the egg whites until frothy.
Stir the melted chocolate into the yolk mixture, then fold some cream and egg white into the chocolate, mixing until smooth. Continue folding these in, alternating between the cream and egg, until all ingredients are mixed together.
Refrigerate for at least two hours before serving.
Note: as this contains raw egg yolks it may not be suitable for pregnant women, so be thoughtful about who you are serving to. The main risk with raw egg is salmonella which is fortunately very rare in New Zealand and I have never had any problems with raw eggs; however, I don't recommend storing this for more than a day or two in the fridge.