• Before you start the pie filling, make sure you have 2 discs of sourdough pastry (pie crust) chilling in the fridge. You can find full step by step instructions for this easy sourdough pastry here.

How To Prepare The Chicken Pie Filling

• Place the chicken breasts in the bottom of a heavy based pot and cover with chicken stock and milk. Add the stock cubes and thyme sprigs and warm the mixture on the stove until it's just simmering. Allow the chicken to gently simmer in the poaching liquid for around 15 minutes or until it's completely cooked through. Do not allow the liquid to boil.
• Remove the pot from the heat and allow to cool slightly before removing the chicken and setting aside the poaching liquid (you'll use this liquid in the pie filling).
• Use a fork to break the chicken into chunks and set aside with the poaching liquid.
• Saute the onion and garlic in a little olive oil in the bottom of a heavy based pot. Allow the onion to get translucent before adding the carrots and celery.
• Saute all the vegetables together for 5 minutes or until cooked through.
• Now, pour the white wine into the mixture and allow the wine to deglaze the bottom of the pan. Let it cook off the alcohol for 5 minutes before you move onto the next step.
• Now add the poaching liquid back into the pan with the butter and sourdough starter. Stir the sauce really vigorously while it warms through. Keep stirring as the sourdough starter thickens the sauce. Do not let the sauce boil.
• Once the sauce has thickened, add the chicken pieces back into the sauce with the salt, pepper and some fresh thyme (leaves removed from the stalk). Stir well to ensure the chicken pieces are well coated in sauce. Set the pie filling aside to cool (it's important that is is not hot when you add it to the pastry).

How To Prepare The Pastry

• Preheat the oven to 390F (200C).
• For this recipe you'll need to prepare the sourdough pie crust in advance. When you are ready to assemble the chicken pot pie, take the sourdough pie crust out of the fridge.
• Separate the pastry into two portions, one for the top and one for the bottom.
• Roll the first portion out until it's large enough to fit your pie dish. For this recipe I used a 1.47Q or 1.4L pie dish. Place the rolled out pastry into the pie dish and gently ease the pastry into the base (don't stretch it). Ensure there is a little overhang so you can join the top crust to the bottom crust and then cut any excess off.
• Fill the pie crust with the cooled pie filling (it's important that the filling isn't hot or it will completely melt the pastry). Fill the pie crust generously as it will sink a bit while cooking.
• Now roll out the second portion of pastry and place it over the top of the pie, cutting off any excess pastry.
• Use a fork, or your fingers, to crimp the top and bottom crust together.
• Cut a small vent in the centre of the pie with a sharp knife.
• Mix the egg and water together and generously brush the top of the pie all over with the egg wash.
• If you haven't already preheated the oven, pop the pie in the fridge while you preheat the oven to 390F (200C).
• When the oven is preheated, place the pie into the oven at 390F (200C) for around 30 minutes. After this time, reduce the temp to 350C (175C) and bake for a further 45 minutes or until the crust is golden and filling is bubbling (you'll be able to see it through the vent you cut in the top).

  See notes for further info on using a pie shield.
• Once the pie is golden and baked through, take it out of the oven and allow it to sit for around 30 minutes before you serve it. This will ensure the sauce thickens and you don't get a soggy pie. If you have time, letting it sit for even longer will give you a better pie!