Melt the chopped chocolate in a large bowl over a pan of simmering water.
In the clean, dry bowl of an electric mixer, whisk the egg whites with the lemon juice on a medium speed until they form soft peaks.
On a high speed, gradually whisk in the sugar.
Continue to whisk until you reach firm peaks.
Take a third of the egg whites and briskly whisk them into the hot melted chocolate, then immediately fold in the remaining egg whites using a large spatula.
Pour the mousse into individual serving bowls or glasses and leave it to set in the fridge for a minimum of 6 hours before serving. Between 6 and 12 hours is the ideal setting time.
Layer the spurge cake, fruit and chocolate mouse to form individual trifles
Recipe by Lisa Fearn, originally featured on Prynhawn Da.
