Cook all the ingredients until the chicken is cooked through.
Strain the chicken and sauce through a colander, and keep the sauce to one side.
Let the mixture go cold, then shred the chicken.
Cut two rounds of pastry, a 23 cm round and a 26 cm round.
Fill the smaller pastry round and seal the top, crimping around the edges with a fork.
Egg wash the top and bake in the oven.
Warm the remaining sauce, which will thicken, and serve alongside the pie.
