My go to Autumnal comfort food,
Pre-heat the oven to 200c. Line a pie dish with one of the rolls of pastry. Prick the base several times with a fork and if there is any pastry hanging over the sides, cut them off. Line the pastry with baking parchment, enough to completely cover the pastry, then fill it up to the top with dried beans and rice. Place in the oven to blind bake for around 10 minutes. This stops Mary Berry's soggy bottom!
Remove the Pie from the oven. Whilst the pie is resting elsewhere, place the chicken pieces, carrots, potatoes thyme, stock and a sprinkle of salt and pepper into a large saucepan. Bring this to the boil and then allow to simmer for 15 minutes, then turn off the heat.
When the chicken stock is nearly cooked, take your smaller saucepan and add the butter and onion, heat on a medium heat and cook for about 5 minutes or until soft. Add in the flour and mix into the onion mixture with your balloon whisk. It should form into a roux. Allow this to cook for around a minute all while whisking.
Add in a ladle of the stock from the chicken mixture. Be sure to just get the stock and none of the chicken or vegetables. Place the stock into the roux while whisking with the balloon whisk. Repeat this until you no longer have any stock left in the chicken mixture.
Pour the milk into the roux, heat it through whilst still continuing to mix with the balloon whisk. As the sauce is heating it should start to thicken.
Once the sauce is near the boil, don't let it boil, instead add it to the chicken mixture and then bring it back to almost boiling point. Add in half the lemon juice, stir and then give it a taste, add in the rest of the lemon and seasoning if you feel it needs it.
Remove the beans, rice and baking parchment. Add your chicken mixture to the pie, brush the pie with the egg wash and then place the second roll of puff pastry on top. Gently push down the sides to seal and again, remove any largely overhanging sides. Make a couple of holes in the top with a fork, Place back in the oven and cook for around 20 minutes or until it turns a lovely golden brown colour.
Serve with baby potatoes and runner beans. Try not to fight over the remaining bits of puff pastry on the dish!