For the pastry, in a bowl, mix together the flour and butter until fine breadcrumbs are formed.

Add the egg and mix until a ball of dough is formed. Wrap in clingfilm and place in the fridge to cool.

In a pan, add the chicken stock and bring to a boil. Add the chicken breasts and reduce to a simmer for 10 minutes.

In a separate pan, melt 25g of the butter and add the sliced leeks. On a low heat, fry for 2 minutes, then add the garlic and cook a further 1 minute. Tip into a bowl and put aside.

Remove the chicken breasts from the stock pan and put on a plate. Pour 200ml of stock into a jug and put to one side.

In a pan, melt the remaining 50g butter. Once melted, add 50g of flour and stir constantly. This will form small, dough like balls. Add the milk slowly, stirring well between additions. Slowly add the 200ml stock and wine and cook on low heat for 3 minutes, stirring. Remove from heat and stir in the cream. Once done, place in a bowl and cover the surface with cling film to prevent a skin forming.

Preheat the oven to 200c/180c Fan/Gas 6. Remove the pastry from the fridge and split into 2 pieces. On a lightly floured surface, roll out so that the pastry is a few cm bigger than the pie dish. Place in the dish and push down to remove any airbubbles.

Chop the chicken into small chunks and add to the leeks. Stir in the sauce and add salt and pepper to taste. Place the mixture into the pie dish. Roll out the second portion of pastry. Beat an egg and brush around the pie edge. Place the pastry pie lid on top and slice carefully around the edge to remove any excess. Pinch around the edge and glaze with egg wash. Pierce a hole in the centre of the pie with a small knife.

Cook in the centre of the oven for 35-40 minutes. Enjoy!