Chicken and ham pie

In this pie the chicken is poached with some flavouring vegetables, which helps to keep the chicken moist and produces a delicious stock which is then used to make the sauce. All cooked under a light layer of buttery puff pastry. If you want to, make up two pies to serve 4 each and freeze one for later use.
Serves 8

1 x 1.75kg/4lb chicken
2 carrots, chopped
2 celery sticks, chopped
3 leeks, cleaned and sliced
4 fresh bay leaves
3 large sprigs thyme
_ tsp black peppercorns
100g/4oz butter
1 large onion, halved and thinly sliced
225g/8oz small chestnut mushrooms, wiped clean and halved
50g/2oz plain flour
75ml/3fl oz double cream
Juice 1/4 lemon
2 tablespoons chopped curly leaf parsley
225g/8oz thickly sliced cooked ham, roughly chopped
450g/1lb fresh puff pastry
1 egg, beaten, to glaze
Salt and freshly ground white pepper

Put the chicken into a large pan with the carrots, celery, 2 sliced leeks, bay leaves, thyme, peppercorns, 1 teaspoon of salt and 2.25 litres/4 pints of water. Bring to the boil, skimming off the scum as it appears, and leave to simmer for 40 minutes.
Remove the chicken from the pan and leave to cool. Strain the stock into another pan and boil rapidly until reduced to 600ml/1 pint. Meanwhile, flake the meat off the chicken in bite-sized pieces, discarding the skin and bones.
Melt 25g/1oz butter in another pan, add the last leek and the onion and cook gently until soft but not browned. Heat 25g/1oz butter in a frying pan, add the mushrooms and toss over a high heat for 2 minutes. Season both.
Melt the remaining 50g/2oz of butter in a pan over a medium heat, stir in the flour and cook gently for 1 minute. Gradually stir in the reduced stock, bring back to the boil stirring constantly, and simmer until smooth and thick. Stir in the cream, lemon juice, parsley and some seasoning to taste, then stir in the chicken, sautÈed vegetables and cooked ham.
Spoon the mixture into a deep ovenproof pie dish (one that holds at least 2.25litres/4 pints) and push a pie funnel or piping nozzle into the centre of the mixture to support the pastry while it cooks. Cover and chill for 1 hour.
Preheat the oven to 200C/400F/Gas Mark 6. Roll the pastry out on a lightly floured surface until it is 2.5cm/1inch larger than the top of the pie dish. Cut off a thin strip from around the edge, brush with beaten egg and press it on to the rim of the dish. Brush with more egg, cut a small cross into the centre of the larger piece of pastry and lay it over the dish so that the pie funnel or piping nozzle pushes through the hole. Press the edges together to seal and crimp them between your fingers to give it an attractive finish. Trim away the excess overhanging pastry, stack up the trimmings and roll them out again. Use to decorate the top of the pie. Brush the pastry with beaten egg and bake for 40 minutes or until the pastry is crisp and golden and the filling is piping hot.