Melt the chocolate in a double boiler. Meanwhile, whip the cream (must be well chilled!) Until stiff. Mix the melted chocolate with the creme fraiche, then carefully fold in the whipped cream.
Leave to cool in the refrigerator for at least 3 hours. Very tasty with passion fruit or grapefruit sauce.
The recipe can be enlarged as required. The scheme is: 3 parts chocolate, 2 parts creme fraiche, 1 part cream.