Melt the two types of chocolate in a water bath and then allow to cool slightly.
Whip the eggs in a bain-marie until thick and creamy, then add the melted chocolate.
Whip the cream until stiff and fold into the egg mixture. Cover and refrigerate for a few hours.
Wash one orange while hot, use a zester or sharp kitchen knife to peel off a few strips of zest and set aside. Squeeze all oranges (yields about 300 ml juice).
Mix orange juice with lemon juice. Add sugar and boil down in a saucepan. Add the orange liqueur.
Divide the sauce evenly among four dessert plates. Use a tablespoon to make dumplings of the chocolate mousse.
Decorate the dessert as desired with chocolate shavings and orange strips.
Preparation Tip:
If you don't want alcohol, you can make this dessert without sauce or add another sauce to taste.