Instructions

1. Heat the oil in a large frying pan and cook the leeks over a medium heat for 5 minutes, until softened. Add the chicken and cook, stirring, for another 5 minutes. Stir in the garlic, thyme and white wine and allow to reduce by half.
2. Pour in the stock and cream and simmer for 5 minutes, until slightly thickened. Spoon into a 2.5 litre pie dish and leave too cool. Preheat the oven to 180C/350F/gas mark 4.
3. Place the pastry over the pie filling, pressing into the sides of the pie dish, crimping with your fingertips. Prick the top of the pastry with a knife to allow steam to escape during the cooking process. Brush the egg over the pastry top.
4. Bake for 35-40 minutes, until the pastry is golden brown and puffed up.