Ingredients

Step by step

1. For the pastry, pulse the flour, thyme leaves, cubed butter and a pinch of salt in a food processor until the mixture resembles fine breadcrumbs. Add the icing sugar and briefly pulse again. In a small bowl, beat the egg yolk (reserve the white) with 2 tablespoons of ice-cold water, then add 2 tablespoons of this to the processor and pulse again until clumps start to form. Reserve the remaining egg mixture. Bring the dough into a ball by hand, then flatten into a disc, wrap and chill for 30-40 minutes.

2. Roll out the pastry on a lightly floured surface to a thickness of about 4-5mm and use it to line a 23cm-diameter fluted tart tin, pressing the dough against the edges and trimming off the excess. Prick the base all over with a fork and chill for at least 30 minutes. Preheat the oven to 200°C, fan 180°C, gas 6.

3. Fill the pastry case with a sheet of crumpled baking paper and baking beans (or uncooked rice), then blind bake on a large baking tray for 20 minutes. Remove the paper and beans (or rice), then return to the oven to bake for 8-10 minutes. Remove from the oven again, brush the base all over with some of the reserved egg mixture, then return to the oven for a final 3-5 minutes until golden brown and crisp (this provides a seal between the pastry and filling). Leave to cool.

4. Meanwhile, for the curd, put the blackberries and lemon juice in a food processor (reserve the zest). Whizz to a purée, then pass through a sieve into a saucepan, discarding the seeds – using the back of a ladle works well for this. Whisk the caster sugar, cornflour and a pinch of salt into the blackberry purée, then set over a medium heat. Whisk until thick and smooth, about 15 minutes. Once it is bubbling, remove from the heat and whisk in the butter until melted. Leave in the pan to cool slightly for 10 minutes. Meanwhile, preheat the oven to 170°C, fan 150°C, gas 3½.

5. After the 10 minutes’ cooling, beat the egg yolks (reserve the whites) and whole egg in a bowl, then whisk in 1 tablespoon of the hot blackberry mixture to temper the eggs. Gradually whisk the egg mixture into the blackberry mixture in the pan. Return to a medium heat, then continue to whisk for 5-8 minutes until very thick and bubbling. Remove from the heat, stir in the lemon zest and set aside while you make the meringue – it should still be hot once spooned into the tart case.

6. In a clean bowl, use an electric whisk to whisk the 5 reserved egg whites to stiff peaks, slowly at first and then increasing the speed. Whisk in the cornflour and cream of tartar, then add the sugar a spoonful at a time, whisking well after each addition. Keep whisking until the meringue is shiny, stiff and doesn’t feel grainy when rubbed between your fingertips. Evenly spread the hot blackberry curd into the baked pastry case. Spoon the meringue on top, making sure it spreads to the tart case edges to seal in the filling. Swirl and peak as you wish with the back of a large spoon. Bake, still on the tray, for 25-30 minutes, until the meringue is pale golden and crisp on the outside. Leave to cool completely and set before slicing and serving.