01 -
Melt 20g butter in a large frying pan over medium-high heat. Add smoked bacon lardons and cook for 5 minutes until caramelised. Add sliced leeks and sauté for 5 minutes until softened. Pour in dry white wine and allow to bubble until completely reduced. Remove from heat and set aside to cool.
02 -
Melt the remaining 50g butter in a large saucepan over medium-low heat. Add flour and cook, stirring, for 1 minute to create a roux. Switch to a whisk and gradually add whole milk and chicken stock, whisking continuously to maintain a smooth sauce. Cook, stirring, for 2–3 minutes until thickened.
03 -
Remove the saucepan from the heat. Stir in double cream and wholegrain mustard. Add the cooked roast chicken and cooled leek mixture. Season with salt and freshly ground black pepper. Transfer the mixture to a large bowl and allow it to cool completely. Once cooled, fold in frozen peas and chopped parsley.
04 -
Spoon the filling into a pie dish approximately 28 x 18cm and 5cm deep. On a lightly floured surface, roll the pastry until 5cm larger than the dish. Brush the rim of the dish with beaten egg, then lay the pastry over the top, allowing it to overhang. Press the pastry firmly onto the rim.
05 -
Brush the pastry lid with beaten egg and cut a small steam vent in the centre. Place the pie in the refrigerator for 30 minutes to allow the pastry to rest. Meanwhile, preheat the oven to 200°C (fan 180°C).
06 -
Bake the pie for 40 minutes until the pastry is golden and crisp. Remove from the oven and let it stand for 10 minutes before slicing and serving.