Method

• 1.
  Place chocolate in a heatproof bowl set over a saucepan of simmering water (don’t let the bowl touch the water) and stir until melted and smooth. Set aside to cool.
• 2.
  To make the peppermint cream, gently whisk yoghurt, icing sugar and two-thirds whipped cream in a bowl until combined. Fold through peppermint extract and transfer to a piping bag fitted with a 1.5cm plain nozzle. (Alternatively, cut a 1.5cm-wide hole in the end of a disposable piping bag.) Chill for 2 hours for the cream to firm up slightly.
• 3.
  To make the chocolate mousse, place eggwhites and a pinch of salt in a stand mixer fitted with the whisk attachment and whisk to stiff peaks. In a separate bowl, whisk caster sugar and egg yolks until mixture is pale and sugar has dissolved. Add melted chocolate to egg yolk mixture and stir to combine. Fold through remaining one-third whipped cream, then gently fold through eggwhite until smooth.
• 4.
  Transfer mixture to a piping bag fitted with a 1.5cm plain nozzle (or a disposable piping bag cut to size as before) and chill for 2 hours to firm up slightly.
• 5.
  At least 1 hour before serving, pipe mousse and peppermint cream randomly, alternating between piping bags, into a 2L (8-cup) serving dish, allowing them to overlap. Chill for 2 hours or until firm.
• 6.
  Cover the after-dinner mints with gold leaf, if using, then tuck mints and mint leaves into the mousse and peppermint cream to serve.