Ingredients

Step by step

1. Melt half the butter in a saucepan, stir in the leeks and some seasoning, with a splash of water, then cover and cook for 8-10 minutes or until softened, stirring once or twice.
2. Meanwhile, heat the oil in a nonstick frying pan and stir-fry the chicken over a high heat for 4-5 minutes. Tip the chicken onto a plate and add the rest of the butter and the mushrooms to the pan. Season and add a splash of water to start the mushrooms cooking. Cook for about 4 minutes until tender, then remove from the heat. Combine the leeks, chicken and mushrooms; cool.
3. Blend the cornflour with a little of the milk to form a paste, then transfer to a nonstick pan and whisk in the rest of the milk, followed by the stock. Bring to the boil, stirring, then simmer for 2-3 minutes. Season and stir in the tarragon.
Tip
These individual chicken pies are topped with reduced-fat (but still deliciously flaky) puff pastry. To finish the pastry on top of the pies first criss-cross the tops using a small sharp knife, then brush with egg yolk and bake.
4. Divide the chicken, leek and mushroom filling between 6 pie dishes (about 250ml capacity), then ladle in the sauce.
5. Preheat the oven to 200°C, fan 180°C, gas 6. Unroll the pastry sheet and cut out 6 discs of pastry, slightly larger than the top of each pie dish, using a saucer or upturned bowl as a guide. Press onto the top of each dish as a lid, with the sides over-hanging. Decorate the pies if you wish, then brush the top lightly with milk or egg yolk and make a steam hole in the centre of each one.
6. Place the pot pies on a baking tray and cook for 20 minutes until the pastry is golden.