Heat the butter in a casserole dish and
cook the bacon for 1 min until it changes
colour. Add the leeks, celery, carrots and
bay, and cook until they start to soften.
Stir the flour into the veg until it goes a
sandy colour, then splash in the cider and
reduce. Pour in the chicken stock, stir,
then add the cream. Season, then bring
everything to a simmer. Add the pheasant
and gently simmer for 20 mins until the
meat and veg are tender. Stir through the
mustard and vinegar, then turn off the heat and cool.
Heat oven to 220C/200C fan/gas 7. Tip
the mixture into a large rectangular dish.
Roll the pastry out on a floured surface,
place over the dish and trim round the
edges, leaving an overhang. Brush the
pastry with egg, then decorate with any
leftover pastry, if you like. Sprinkle with a
little sea salt. The pie can now be frozen
for up to 1 month; defrost completely
before baking. Bake for 30-35 mins until
golden. Remove from the oven and leave
to cool for 5 mins before serving.