Melt the chocolate.
Place the chocolate in a thin-sided bowl and suspend over a gently simmering bain-marie, ensuring that the bowl does not touch the water. Remove from the heat, allow the chocolate to melt, stir until smooth. Remove.
Prepare the mousse
Whip the cream with the vanilla seeds until just stiff, carefully fold into the chocolate, fill the dishes, cover and allow to set in the fridge for approx. 1 hour.
Mix the nectarines, raspberries, sugar and lemon liqueur, cover and leave to steep for approx. 10 mins. Distribute the fruit compote on the mousse.