Heat the oven to 220 C, 380 F or Gas Mark 6.
Tear the turkey flesh from the bone in large chunks and discard the skin and bone.
Heat the butter in a large pan and add the spring onions.
Cook for a few minutes until softened.
Add the mushrooms and cook for five minutes or so until lightly coloured.
Stir in the flour and cook for another minute, then gradually add the milk.
Add the cream and simmer until the sauce thickens.
Stir in the organic turkey and tarragon.
Roll out the pastry to a thickness of a 20 pence piece and cut out to either the shape of 4 individual dishes or roll over a large dish, either works well!
Divide the turkey into four dishes or into a large dish.
Brush the rims with beaten egg.
Lift pastry onto the pie dish/dishes, trimming off any excess. Press down and crimp the edges with a fork.
Make a couple of slits in the pastry to let the steam out and brush over the pasrty with the remainder of the egg.
Bake for about 15 - 20 minutes until the pastry is crisp and golden brown.
Serve with seasonal vegetables.