1 tbsp finely sliced crystallised ginger, to serve
single cream (optional)
Whisk the egg whites to form stiff peaks. Set aside.
Break the chocolate into pieces and put in a bowl. Pour the cream into a saucepan and heat until almost boiling.
Pour the hot cream over the chocolate, stirring continuously. Continue to stir until the chocolate has completely melted. Add 4 tbsp orange juice, 2 tbsp zest and the crystallised ginger. Leave to cool slightly, then stir in egg yolks.
Using a large metal spoon, carefully fold in two large spoonfuls egg whites; once combined, gently fold in the remaining whites.
Spoon the mixture into small pots or espresso cups and chill in the fridge for at least an hour. Top with slivers of ginger, before serving with cream, if desired.