Dice the chicken and lightly fry in a pan until it starts to turn white.

Chop the mushrooms and add to the chicken. Cook both until chicken is fully cooked. Take off heat and leave aside.

To make the white sauce, melt the butter in a pan and gradually add the sifted flour, stirring constantly for 2 min.

Combine the milk and chicken stock and slowly add to the butter. Bring to boil and leave to simmer for 10 mins. Keep stirring the sauce throughout.

Pour the sauce over the cooked chicken and mushrooms and season with salt and pepper. Leave to cool slightly.

Roll out the pastry and line the baking tin with it. Brush the edges with the beaten egg.

Pour the chicken mix into the pastry case and roll out and cut the pie top. Press the edges together with a fork and make a few slits for steam to escape.

Brush the top of pie with egg and cook in the oven for 25-30 mins or until pastry is cooked and golden brown.