Method

Preheat oven to 220ºC/425ºF/Gas Mark 7

1. Melt half the butter in a large heavy-bottomed pan and gently fry the leeks until soft. Using a slotted spoon, remove the leeks and put to one side, then add the remaining butter to pan and seal the chicken on all sides.
2. Add the cream and chicken stock and bring to the boil, then add the halved potatoes and lightly boil for 10-15 minutes.
3. Add the thyme leaves and simmer gently until stock is reduced. Meanwhile lightly blanch the asparagus spears in boiling water, drain and chop the stalks reserving the top part and tips.
4. Add the leeks and chopped asparagus to the chicken mixture, season to taste and allow to cool. Once cooled divide between 6 individual pie dishes or similar.
5. Cut the pastry into 6 equal pieces and roll out each large enough to form a lid to the pie dishes. Slice the cheese thinly and lay on top of the chicken mixture in each dish. Brush the rims of the dishes with beaten egg and cover with the pastry, pinching at edges to seal well to dish.
6. Score lines across top of lids and make a small hole in two corners or ends of the pies, brush tops with beaten egg.
7. Place dishes on a baking tray and bake for 15-20 minutes until pastry has risen and is golden brown.
8. Just before the pies are done, re-heat the reserved asparagus tips in boiling water.

Place the asparagus tips in the holes in pie tops to serve