Espresso tart with hazelnut pastry and Kahlúa cream

Method

• step 1

  Put the flour, hazelnuts and sugar in a food processor or bowl and whizz or rub in the butter until the mixture looks like breadcrumbs. Add the egg yolk and pulse or mix until you have a rough dough (add 1 tbsp very cold water to combine if needed). Bring the dough together with your hands and knead it briefly on a floured surface, then roll it out and use it to line a rectangular 35cm x 12cm tart tin or a 24cm round tart tin (you may need to patch it up a bit with some pastry scraps). Leave some pastry sticking up above the side of the tin and chill the pastry case for 30 minutes.

• step 2

  Heat the oven to 190C/fan 170C/gas 5. Line the pastry with parchment or foil and baking beans, and bake for 15-20 minutes. Take out the foil, brush with the egg white and bake for another 5 minutes. Trim off the excess pastry and cool the case completely.

• step 3

  Heat the cream, sugar and espresso powder to just below boiling point and pour the mixture over the chopped chocolate and butter, stirring until the chocolate is melted. Whisk in the Kahlúa. Pour the mix into the tart and leave to set at a cool room temperature or in the fridge.

• step 4

  To serve, whisk the cream with the icing sugar and Kahlúa to just beyond soft peaks. Spoon it into a pastry bag fitted with a round, straight-edged nozzle and pipe small dots on top of the tart.