Jo Pratt's Blueberry Pie with Lemon Pastry

With their balance of acidity and sweetness, blueberries are delicious in pies.

To Prepare The Filling

1. 1

   Place the blueberries in a saucepan with the sugar and lemon juice.

2. 2

   Place over a medium heat and bring to a simmer, stirring occasionally.

3. 3

   Cook for a couple of minutes.

4. 4

   Mix the arrowroot with a little water to make a loose paste and stir into the pan.

5. 5

   Simmer for 2-3 minutes, stirring occasionally before removing from the heat and leaving to completely cool.

To Make The Pastry

1. 6

   Sieve together the flour and icing sugar into a large mixing bowl or into the bowl of a food processor.

2. 7

   Add the butter and lemon zest, and either rub lightly between your fingers or blitz briefly until you have a fine crumbly mixture.

3. 8

   Add the beaten egg and about 1 tablespoon of cold water, then gently and quickly work together until you have a ball of dough.

4. 9

   Divide in half and wrap each piece in clingfilm.

5. 10

   Place in the fridge to chill for about 30 minutes.

To Assemble The Pie

1. 11

   Preheat the oven to 200C/180C fan/gas 6.

2. 12

   Remove the chilled pastry from the fridge.

3. 13

   Roll out on a lightly floured surface into two disks using one to line the base and sides of a pie dish, measuring 18-20cm (7-8in) in diameter and about 4cm (1½in) deep, and the other one big enough to cover the surface of the dish, with about 2cm (¾in) overlapping the edge.

4. 14

   Spoon the blueberry filling into the pastry-lined pie dish and then top with the remaining piece of pastry.

5. 15

   If you have enough time, place in the fridge for about 30 minutes for the pastry to relax, but don't worry if you can't.

6. 16

   Brush over the surface of the pie with the egg white and sprinkle the caster sugar over the top.

7. 17

   Pierce a hole in the middle of the pastry with a knife and then place in the oven for about 30-35 minutes, or until the top is golden and crispy.

To Serve

1. 18

   Once cooked, the pie can sit for at least 30 minutes and will still be hot enough to serve, with either vanilla ice-cream, custard, cream or crème fraîche.