Black grape & lime pie

First, make the pastry: cut the butter into small pieces, tip onto a plate and freeze for 10 minutes. In a large bowl, stir together the flour and sugar, add the butter and use your fingertips to rub it into the flour until it feels like small flat slivers (don’t take it as far as fine breadcrumbs). Add the vinegar and 1 tbsp cold water, then bring the dough together with your hands, adding 1-2 tbsp more cold water, if needed, to make a firm ball. Divide in 2 and press into flat rounds. Wrap in baking parchment and chill for 15 minutes.

Dust a work surface with flour, then take one of the pastry discs and roll it into a 25cm circle. Use to line a 23cm pie dish; chill. Line a large baking tray with parchment. Dust the work surface with flour again and roll out the remaining dough into another 23cm circle; transfer to the baking tray and chill.

For the filling, put the grapes, cinnamon, vanilla and sugar in a pan and bring to the boil. In a small bowl, use a fork to mix together the zest of 3 limes, all the lime juice and the cornflour; add to the pan. Simmer for 2 minutes, then scrape into a bowl and set aside to cool. Once at room temperature, transfer to the fridge to cool completely.

Preheat the oven to 200°C, gas mark 6. Pour the grape mixture into the chilled pastry base. Brush the edges with a little beaten egg, then carefully lay the second circle of pastry on top. Press the edges together with a fork and trim with a knife. Cut a small slit in the middle of the pie and brush the top with the remaining beaten egg. Bake for 20 minutes, then lower the heat to 180°C, gas mark 4, and bake for another 30 minutes or until the crust is golden. Allow to cool slightly (about 10 minutes) or completely before serving. Mix the crème fraîche with the remaining lime zest and serve alongside the pie.