Chocolate mousse

150 g finest quality bitter chocolate
1/4 cup espresso coffee
1/2 tbsp butter
3 yolks
3 egg whites

Melt the chocolate with the coffee in a double boiler. Stir and when it forms a cream remove from heat, add the butter and the egg yolks immediately stirring in well. You must put the egg yolks in while the chocolate is hot as it cooks them. Cool the chocolate cream and whip the egg whites to stiff peaks. Fold in the egg whites gently and refrigerate for 24 hours. Remove about half an hour before serving.
If you are feeling really greedy serve with slightly sugared whipped cream.