Caramel almond slice

For the pastry, pulse the flour, butter, icing sugar and a pinch of salt in a food processor until the mixture resembles sand. Tip into a bowl and add the egg yolk and 1-2 tbsp very cold water, and mix until the pastry starts to come together. gently knead the dough then flatten into a disc, cover with clingfilm and chill for 1 hour.

Heat the oven to 180c/fan160c/gas4. Dust the work surface with flour, roll the pastry to pound-coin thickness and use to line a 20 x 30 cm loose-based rectangular tart tin. trim the excess and prick the base with a fork. chill for another 20 minutes, then line the tart case with baking paper and baking beans and bake for 15 minutes. Remove the beans and paper and cook for 10 minutes until pale golden.

Meanwhile,tomakethefilling,tipthe caster sugar into a pan. Add 100ml of cold water and put over a very low heat to gently dissolve. Raise the heat and continue to boil until the sugar becomes an amber-coloured caramel (swirl the pan to make sure it cooks evenly). take off the heat and carefully pour in the cream, butter and grand Marnier. Return to the heat and continue to cook, stirringconstantlyforanother2minutes until smooth and toffee coloured. take off the heat, add the flaked almonds and leave to cool for 5 minutes.

Beat the egg, egg yolk and lemon zest together in a bowl, then pour in the almond caramel mixture, stirring constantly until smooth. Stir in a large pinch of sea salt flakes and carefully pour the mixture into the baked tart shell. Slide back into the oven on a baking sheet and cook for a further 20-25 minutes until the filling has set and is golden brown. Cool to room temperature. Drizzle the top of the tart with melted dark chocolate to serve if you like.