It's important to cook the meat a day ahead, so that you can discard any fat that has risen to the top, and so that the pastry doesn't slump in the face of a too-warm filling, so up to 48 hours ahead -make the pastry. Whizz the flour and a
pinch of fine sea salt together for a few
seconds in a food processor, then add the
butter and whizz until the mixture looks like
coarse breadcrumbs. Whisk together the
egg yolk and 3 tbsp water and whizz with
the pastry until it collects in a ball. Wrap in
cling film and leave it to rest in the fridge
for at least one hour.
Cut button-mushroom-sized lobes of
kidney from the white central core
(discarding). Cut the beef into bite-sized
cubes and cut the mushrooms into chunks.
Heat 1 tbsp of the oil in a large, heavy
frying pan over a medium-high heat. Throw
in the kidney and fry until lightly coloured.
Tip into a colander to drain.
Wipe out the frying pan and return it to a
low-medium heat, adding 25g/1oz of the
butter and 1 tbsp oil. Tip in the onion and
fry for 10 minutes, stirring occasionally, until
soft and slightly golden. Transfer to a large
casserole, using a slotted spoon.
Preheat the oven to 160C/gas 3/fan
140C. Tip the 85g/3oz flour into a large
plastic bag, and season it generously. Throw in the beef and shake until lightly
floured.Return the frying pan to a mediumhigh
heat, adding a little more oil and butter
if needed. Shake off any excess flour
(reserving it) then fry the beef in batches
until golden-brown. As each batch is done,
transfer it to the casserole.
Adding more oil and butter to the frying
pan if necessary, fry the mushrooms for
about 2 minutes until starting to wilt, then
add them to the casserole with the drained
kidneys, hot water, bouillon powder and
bay leaf, plus the excess flour in the bag if
you like a thick gravy. Stir well, cover and
cook in the oven for 75-90 minutes until the
meat is tender and the sauce is thick. Cool
thoroughly, then put in the fridge (preferably
overnight) so any fat will solidify – it can
then be skimmed off and discarded.
In the morning - return the pastry to cool room
temperature, then roll it out thinly on a wellfloured
surface. Invert a 28-30x23cm,
6.5cm deep pie dish on to the pastry.
Mentally add an extra 1cm all round, then
use the dish as a guide to cut out the pastry
lid. From the remnants, cut out enough
6cm-wide strips of pastry to go round the
dish – they should cover the flat rim and
about halfway down the insides.
Lightly butter the rim of the dish and line it
with the strip(s) of pastry, sealing any joins
with a little dab of water. Butter the
shoulders of a pie raiser or an upturned
egg cup and stand it in the middle. Spoon
in the meat mixture to come level with the
top of the dish. Don’t overfill: reserve any
excess gravy to serve hot with the pie.
Brush the pastry rim with a little water,
then drape the pastry lid over it, pinching
the edges to seal. Cover with cling film and
keep in the fridge if not baking immediately.
Finally, an hour before serving - preheat the oven to 200C/gas 6/fan 180C.
Make four slashes in the lid of the pie, then
brush with the egg wash. Bake for 35-45
minutes until the pastry is golden brown,
turning the heat down 10-20º after about
20 minutes. Remove the pie from the oven
and leave it to rest for around 10 minutes
before cutting into it.