Decadent Chocolate Mousse recipe.  (it has to be decadent, anything around here using chocolate  is called decadent)
For a decent quantity, you need:

    * 200-250g of dark chocolate (Belgian of course) 
    * 4 eggs
    * 4/10 litres of whipping cream
    * 4 teaspoons of sugar

and you don t absolutely need it, but it adds something to the taste:

    * 2 coffeespoons of instant coffee

Mix the yolks and the sugar in the bowl you want your mousse to end in.

The order of the rest depends on whether you use a double boiler or not.
If you use a double boiler:

    Melt the chocolate in the double boiler, making sure the water never gets to boil. Meanwhile, beat the egg whites until stiff. Beat the whipping cream in a separate bowl.

If you don t use a double boiler:

    Start by raising the egg whites and the whipping cream (separately). Then, melt the chocolate directly in a pan, but make sure it never burns. To help you, use a bit of extra whipping cream.

Add the melted chocolate to the yolks-sugar mix. Try to get them to mix as much as you can. Before the chocolate cools down completely, pour some whipping cream into the mix and stir with a wooden spoon. Then fold some egg whites into your mix. And so on. It is very important that you alternate, and be really gentle all along that process.
Let stand in the fridge for at least 1 hour. That's it!


http://www.recipe-source.com/desserts/mousse/indexall.html