Step 1

Melt the chocolate, cream and butter in a bowl set over a pan of simmering water and add a pinch of fine sea salt. Remove from the heat and fold in the egg yolks. Whisk the egg whites with the sugar to stiff peaks. Fold half the whites into the chocolate, then fold in the remaining half. Spoon into a large piping bag and chill for at least two hours.

Step 2

For the pâte sucrée, beat the icing sugar into the butter. Gradually beat in the egg, then add the flour, cocoa powder and a large pinch of fine sea salt and mix until smooth. Shape into a block and chill for two hours.

Step 3

For the salted caramel sauce, put the muscovado sugar, cream and glucose in a pan and bring to a boil. Remove from the heat. Tip the golden caster sugar into another pan and gently heat until melted, turn up the heat and cook to an amber-coloured caramel. Carefully add the hot cream and mix. Simmer until thickened and darker, and reading 102C on a sugar thermometer. Stir in a pinch of sea salt, the lemon juice and cool completely.

Step 4

Heat the oven to 200C/fan 180C/gas Bring the pâte sucrée to room temperature, then roll out to 2-3mm thick and cut six 8cm rounds to line six individual tart tins. Lightly prick the bases with a fork, fill with baking beans and blind bake for 8 minutes. Remove the baking beans and bake for 2 minutes or until dry to the touch. Carefully remove the tarts from the tins.

Step 5

Heat the oven to 160C/fan 140C/gas Put the tart cases on a baking tray, add 1 tsp of set caramel to the centre of each and pipe in the mousse until level with the top. Cook for 8-10 minutes or until wobbly but set. Dust with cocoa powder.