Place washed and peeled onion, carrot and celery stalks in a large saucepan. Cover with 6 cups of water. Add stock cube. Bring to the boil.

Add the chicken breasts and allow to simmer until chicken is cooked. This should take about 30 minutes depending on how big your chicken breasts are
Once cooked allow to cool. Separate broth, keep veg and chicken

Heat oil in a frying pan.
Add the cleaned and finely sliced leeks together with bacon bits
Sauté for about 5 minutes until the leeks are tender.

Gradually add the coconut milk, stirring until mixture is smooth.
Stir constantly over medium heat until sauce boils and thickens. Remove from heat.

Chop or pull apart the previously poached chicken breasts and add it to the sauce mixture, season to taste; stir gently until combined and allow to cool slightly.

For pie with a Pastry bottom, line the pie dish with pastry and cook at 220 for 10 minutes first. Poke holes in the base before putting in oven to prevent rising.

Once cooled spoon the mixture into a baking dish.

Brush edge of pastry dish with beaten egg yolk.
Top with puff pastry, crimp down the edge to seal using your fingers or by using a fork; trim and brush the top with the remaining egg yolk.

Decorate with any pastry trimmings if you desire and cut 3 slits in the centre of the pie to allow the steam to exit during baking.

Bake in a moderately hot oven (220°C/430°F) for 10 minutes then lower heat to moderate (180°C/350°F) and cook a further 20 minutes. Should the pastry begin to brown too quickly cover with a sheet of foil.