Method

1. Melt the chocolate with the orange zest in a bowl over a pan of gently simmering water, or alternatively in the microwave in a microwave-safe bowl on a MEDIUM setting in 20-30 second intervals. Set aside to cool.
2. Whip 300ml of the double cream until you have soft peaks, then carefully fold in the cooled chocolate mixture.
3. Divide the mousse between 6 small glasses or ramekins.
4. Whip the remaining cream to soft peaks and spoon over the mousse. Garnish with orange zest and chocolate shavings to serve.