Soak the gelatine leaves in cold water. Break the chocolate into pieces and place in a heatproof bowl.
Bring the cream to the boil and then pour it over the chocolate. Add the softened gelatine leaves and stir until smooth and well combined.
Allow to cool and then mix in the egg whites. Transfer to a siphon and charge with a gas canister. Keep chilled until ready to serve.
Quarter the strawberries and finely slice the mint leaves. Mix together with the Chambord until the edges of the strawberries start to break down a little. Cool in the fridge.
Crumble the biscuits into the bottom of individual glasses and spoon some of the strawberries on top. Finally, add mousse from the siphon on top and garnish with ground pistachios and a sprig of mint.
«Use any type of seasonal fruit to make this an all year round dish.»