Method

• 1.
  For the mousse, place chocolate in a large bowl. Heat cream in a small saucepan until almost boiling, then pour over the chocolate. Stand for 1 minute. Whisk until combined. Set ganache aside and keep warm to prevent it firming too much.
• 2.
  Place sugar in a small saucepan with 50ml water. Cook, stirring, over medium heat until sugar has dissolved. Increase heat to high and cook, without stirring, until syrup reaches 115°C on a sugar thermometer.
• 3.
  Meanwhile, in a stand mixer fitted with a whisk attachment, beat egg yolks until pale. Slowly add the hot syrup to gently cook the yolks. Fold mixture through the chocolate ganache until thoroughly combined.
• 4.
  In a separate medium bowl, whisk the extra cream until soft peaks form. Gently fold through the chocolate mixture in 3 batches. Cover and chill for at least 3 hours.
• 5.
  For the salted caramel, place sugar in a high-sided, heavy- based pot over medium-high heat and leave untouched until sugar dissolves evenly, then gently swirl pan until sugar reaches a dark golden colour, around 166°C. Reduce heat to low and whisk cream in slowly to incorporate evenly. Remove pan from heat and whisk in butter, one piece at a time, until melted and well incorporated. Whisk in sea salt. Transfer to a large bowl and set aside for 20 minutes to cool slightly before serving (if left for too long, the caramel will firm up too much).
• 6.
  Scoop a big spoonful of chocolate mousse into a serving bowl and make a well in the middle. Add a dollop of creme fraiche into the well. Make a well in the middle of the creme fraiche. Add a dollop of the salted caramel into the well. Top generously with mochi pieces and toasted buckwheat to serve.