Mocha mousse for a crowd

Method

1. Heat both types of chocolate and 265ml of the cream in a large bowl set over a pan of barely simmering water (don’t let the water touch the bowl) until the chocolate has melted and combined with the cream – it will thicken as it does. Remove the bowl from the pan and set aside to cool a little.
2. Soak the gelatine leaves in a jug of cool water for 5 minutes. In a small pan combine the espresso and camp coffee, then heat gently. Once warm, squeeze out the gelatine and stir into the coffee until dissolved.
3. Whip the remaining 265ml cream in a large bowl until it reaches soft peaks (that flop over when the whisk/beaters are removed). Put the egg yolks and 100g sugar in another large bowl and use an electric mixer to whisk until the mixture is pale, thick and the sugar has dissolved. Transfer half the egg mixture into the whipped-cream bowl and add the coffee mixture. Use the electric mixer to whisk together until silky and combined.
4. Add a little of the chocolate mixture to the remaining egg mixture, then stir it in. Stir in the remaining chocolate mixture.
5. In a third bowl (or wash and dry the bowl that had the chocolate mixture in it), use a clean electric whisk to beat the egg whites to soft peaks. Add the remaining 165g sugar a little at a time while whisking continuously until combined in a thick, glossy meringue with stiff peaks.
6. Gently fold half the meringue into each mixture (a large metal spoon or balloon whisk are good for folding). Pour the coffee mousse into the base of the large serving dish and spread evenly. Spoon over the chocolate mousse (don’t pour this one as it will disrupt the coffee mousse layer underneath). Cover the dish with a beeswax wrap or plate (without letting it touch the surface) and chill for at least 3 hours to set. Serve at the table for everyone to help themselves. It’s great served with a drizzle of extra-virgin olive oil and a pinch of salt flakes.