melt the chocolate, butter and sea salt in a bowl set over hot water. Do not let the mix get too hot.

Once melted, mix in the egg yolks until smooth.

In a separate clean bowl, whip the egg whites using a hand-held whisk on a medium speed until frothy and stiff, then gradually add the sugar until a thick, glossy meringue is formed.

Mix one-third of the egg white into the chocolate mix to loosen it then fold in the remaining egg white in two additions. Chill the mousse in the fridge for at least 2 hours.

melt the butter in a saucepan over high heat, cook until it begin to brown, this won't take long.

In a separate saucepan, add the cream and light muscovado sugar and bring to a simmer. Gradually mix in the browned butter until smooth.

Remove from the heat and add the milk chocolate, mixing until smooth. Allow to cool fully.

cut the brioche in half and butter each side well, then sprinkle with the caster sugar.

Heat a frying pan over a medium heat and place the brioche pieces face down to caramelise the sugar and butter, this will take 1-2 minutes. Take care not to over-caramelise as it will taste bitter. Set aside.

To make the white chocolate straws, place a baking tray with baking paper in the freezer.

Melt half of the white chocolate over a pan of hot water. Remove from the heat and mix in the remaining chocolate until cooled.

Spoon the chocolate into a piping bag, then pipe long straws of chocolate onto the cold baking tray lined with paper and place in the freezer until needed.

To serve, spread a thick layer of caramel onto the brioche. Pipe or spoon the mousse on top of the caramel, then close the bun. Stack with white chocolate straws, dust with icing sugar and place the filled brioche in the fridge for 30 minutes before serving. Napkins will be needed as this is indulgent and a bit messy to eat!