Method

1. Begin by making the berry filling. Place the berries and sugar in a pan and cook over a gentle heat for 20 minutes, stirring occasionally, until the liquid forms a syrup. Set aside and leave to cool completely
2. Meanwhile, make the custard. Whisk together the egg yolks and sugar in a large mixing bowl for 2 minutes until pale and fluffy, then mix in the plain flour, cornflour and a dash of milk to loosen up the mixture. Whisk until completely combined and set aside
3. Place the milk and vanilla seeds in a pan and bring to the boil over a medium heat. Quickly whisk in the egg and sugar mixture and continue to heat through until the custard thickens, stirring continuously to help the cornflour cook out
4. Once thickened, pour the custard into a deep baking tray or tin and cover with clingfilm – this will help it to cool quicker. Place in the fridge for 30 minutes
5. Remove the pastry from the fridge 20 minutes before using to allow it to come to room temperature
6. Preheat the oven to 200°C/gas mark 6 and line a large baking tray with baking paper
7. Roll the pastry out to a thickness of a pound coin and cut out 4 circles, each about the size of a small side plate or roughly 18cm in diameter
8. Spread a layer of the chilled custard over half of each circle, leaving a border. Make a slight indent in the middle of the custard and add a good spoonful of the cooled berries
9. Dampen the pastry border with a little water and fold over the plain half to cover the fillings, making a semi-circle shape. Use a fork to seal the edges together, pressing down firmly to create a lined pattern
10. Make 3 small slashes with a sharp knife in the top of each pie to allow steam to escape, then brush the tops liberally with the beaten egg to glaze. Sprinkle over a thick coating of Demerara sugar and transfer the pies to the lined tray
11. Bake for 10 minutes then turn the oven temperature down to 160°C/gas mark 3 and bake for a further 15 minutes until golden and crisp
12. Remove the pies from the oven and leave to cool for a few minutes as the filling will be extremely hot. Serve warm with vanilla ice cream, or leave to cool completely if not eating straight away