Roast chicken pie

Ingredients
Short and puff pastry bottom and top
½ roast chicken shredded
1 tbsp olive oil
3 rashers smoked streaky bacon, chopped into lardons
1 leek or onions, sliced into rounds
45g butter (or less)
45g plain flour (or less0
120ml milk
100ml chicken stock
50g peas
Sliced mushrooms (2-3)
1 tsp wholegrain mustard
25g pack parsley, roughly chopped
1 egg, beaten, to glaze

Makes 1 lg(23cm) pie or if you have lots of filling 1 lg and 1 sm.

Method
Heat oven to 220C/200C fan.
In a large, non-stick frying pan, heat the oil, then fry the bacon. Once browned, reduce the heat, add the leeks/onions and cook until they have softened. Mix the butter and flour into a paste and add to the pan, stirring to coat the bacon and leeks. Add sliced mushrooms and cook a couple of mins. 
Slowly add the milk, stirring constantly to ensure the mixture doesn’t get lumpy. Add the chicken stock and peas, cook for 2 mins, then add the mustard and remove from the heat.
Add chicken to the pan with the parsley.

Line pie dish, spoon in filling and top with pastry. Crimp and seal the edges. Brush with the beaten egg, then cut a few slits in the middle for steam to escape. Bake for 45 mins until golden. 

Chooks note: I sprinkle the top with slightly crushed fennel and/or carraway seeds. The pie freezes well. The pie in the pic was made with all short crust pastry but s flakey top is lovely.