Method

• 1.
  Melt chocolate in a heatproof bowl over a pan of simmering water (don't let the bowl touch the water). Remove from the heat, then stir until smooth. Set aside to cool.
• 2.
  Meanwhile, separate 2 eggs and set the eggwhites aside. Place the 2 egg yolks, remaining whole egg, vanilla extract and 2 tablespoons sugar in the bowl of an electric mixer and beat until thick and pale.
• 3.
  Lightly whip the thickened cream to soft peaks. Fold melted chocolate and cream into egg mixture until combined.
• 4.
  In a separate bowl with clean beaters, beat eggwhites with remaining 1 tablespoon caster sugar until soft peaks form. Fold into egg mixture to just combine, keeping as much air in the mixture as possible. Place mousse in a glass serving dish and cover with a layer of Lindor balls. Chill for 4-6 hours until mousse is set, then serve.
• 5.
  Begin this recipe at least 6 hours in advance