Chop the chicken into bite-sized pieces. Put into a large mixing bowl with lemon juice, parsley, a little salt and generous with the pepper. Mix thoroughly.
SAUCE: blitz together the cream, cheese, garlic, mustard and cornflour in a jug or mixing bowl using a stick blender. Then stir in the stock.
Melt the butter or oil in a large frying pan and add your chicken. Cook over a high heat for 5 minutes.
Add the leeks, mushrooms and thyme to the pan, stirring them well. Cook for 3-4 minutes.
Pour in the sauce, increase the heat to high, stirring frequently, for around 3 minutes, or until the sauce has reduced.
Stir through ham hock and leave the mixture to cool.
FOR THE PIE: Oven at 180°C fan. Grease your pie tin and fill with shortcrust pastry.
25 mins for the shortcrust blind with baking beans and a baking sheet, remove the beans and pop back in for 5 mins empty, then fill - 45 mins at 180°C at least with the puff pastry lids on and egg wash and rest: depending on your pastry it could take up to an hour.
