Chicken and wild mushroom frying pan pie

Method

1. For the pastry, place the flour in a mound on a clean work surface and make a well in the centre.
2. Place the butter and salt in the well and work them together with the fingertips of one hand, gradually drawing the flour into the centre with the other hand. When the cubes of butter have become small pieces and the dough is grainy, gradually add 125ml of ice-cold water and mix until it is all incorporated. But don’t overwork the dough; the butter should give a marbled effect to the pastry and not be mixed in fully.
3. Roll the mixture out on a lightly floured surface into a 2.5cm-thick rectangle, wrap in cling film and refrigerate for 20 minutes.
4. Flour the work surface and roll out the pastry into a 40 x 20cm rectangle. Fold one short side over by one-third, then the other short side on top of it, as though you were folding a business letter. Turn 90°. Roll the block of pastry into a 40 x 20cm rectangle as before and fold it into three again. These are the first two turns. Repeat twice more to make four turns in total.
5. Wrap the pastry in cling film and refrigerate for at least 30 minutes before using.
6. Meanwhile, make the filling. Heat a large (24cm) ovenproof frying pan until hot, add the butter and, when it foams, add the shallot and garlic and fry for one minute, then add the chicken and fry until just coloured. Add the mushrooms and fry over a high heat for two or three minutes until just softened, then add the madeira and set the mixture alight with a match, standing well back.
7. When the flames subside, pour in the stock and bring to a simmer, then add the tarragon and cream and simmer for five minutes. Check the seasoning, then set aside to cool.
8. Preheat the oven to 200°C.
9. Roll out the pastry on a lightly floured work surface until it is 5cm wider than the frying pan and 4–5mm thick. Brush the edges of the frying pan with the egg. Lay the pastry over the filling and crimp at the edges. Trim away any excess pastry and brush the top of the pie with the remaining egg. Decorate with any pastry trimmings, if you like.
10. Bake in the oven for 25 minutes, or until the pastry is crisp and golden and the filling is bubbling.