- Pre-heat oven to 190°C, Gas 5.
- Add butter and oil to heavy based pan and sauté sliced leeks and slice mushroom together on a low heat until soft but not coloured.
- Gradually add plain flour taking care to mix thoroughly.
- Gradually pour in hot stock, stirring carefully and letting mixture simmer until you have a thickish sauce.
- Add chicken pieces to sauce mix and season to taste.
- Allow to cook for a further 5-8 minutes.
- Turn off heat and stir in crème fraiche.
- Spoon the mixture into a pie dish. Roll pastry sheet over pie dish, allowing it to hang casually over the sides. Brush carefully with beaten egg and milk.
- Make 4 small slits on top of the pie to let the steam out during cooking.
- Place in middle shelf of oven for 25-30 mins until piping hot and golden brown.
Gaynor's Tip: If you don't have a traditional pie dish you can easily make a funnel out of thick tin foil by rolling it into a short tubular shape around your finger.