Chicken and Leek Pie

Put the chicken, onion, carrot, celery and herbs in a flame proof casserole and cover with cold water. Cover and bring to the boil, then reduce the heat and simmer for 1 hour, or until the chicken is tender and the juices run clear when a skewer is inserted into the thickest part of the meat. Remove the chicken from the casserole. Discard the skin. Remove the meat from the carcass, cut into chunks and reserve. Sieve the chicken cooking liquid, discarding the vegetables and herbs, and reserve.

Preheat the oven to 190ºC / 375ºF / Gas Mark 5. Heat the oil in a large frying pan and cook the onion until soft but not browned. Remove from the pan with a slotted spoon and set aside. Melt the butter in the frying pan and cook the leeks for 5 minutes. Stir in the flour and cook, stirring constantly, for 2-3 minutes. Gradually add 425ml / 15 fl oz of the reserved cooking liquid and cook, continuing to stir constantly, until the sauce is thick and smooth. Stir in the mushrooms and ham. Mix the cooked chicken with the onion and the sauce and stir in the cream. Season to taste with salt and pepper and spoon into a baking dish.

Brush each sheet of filo pastry with a little of the vegetable oil, then scrunch up and place over the chicken mixture. Bake in the preheated oven for 30 minutes until the filo pastry topping is brown and crisp.