Heat the chicken stock in a lidded saucepan. Add the chicken breast and bring to low simmer. Cover with a lid and cook for 10 minutes. Remove the chicken breast from the water and place on a plate. Pour the cooking liquor into a bowl.

Melt 25 g of butter in a saucepan over a low heat. Stir leeks and fry for 2 minutes.

Add garlic and cook for 1 minute.

Add remaining butter and stir in the flour as soon as the butter has melted. Cook for 30 seconds.

Slowly pour the milk into a pan, little by little. Gradually add 250 ml of the reserved stock and the wine.

Stirring until the stock is smooth and thickened slightly. Bring to a gentle simmer for 3 minutes.

Season the mixture. Remove from the heat and stir in the cream. Pour into a large bowl and cover the surface of the sauce with cling wrap to prevent a skin form. Set aside to cool.

Preheat the oven to 200 C. Put a baking trays in the oven to heat.

For the pastry, put the flour and butter in a food processor and blend until the mixture resembles fine breadcrumbs. Add the beaten egg and water and blend until mixture form a ball.

Portion off 250 g of pastry for the lid.

Roll the remaining pastry out on a lightly floured surface, turning the pastry frequently until around 5mm thick and 4 cm larger than the pie dish.

Press the pastry firmly up the sides, making sure there are no air bubbles. Leave the excess pastry overhanging the sides.

Cut the chicken breast into 3 cm pieces. Stir the chicken, ham, leeks into the cooled sauce.

Pour the chicken filling into the pie dish. Brush the rim of the dish with beaten egg. Roll out reserved pastry for the lid.

Cover the pie with the pastry lid and press the edges together firmly to seal. Trim any excess pastry

Make a small hole in a centre of the pie. Glaze the top of the pie with beaten egg.