Heat oven to 200C/180C fan/gas 6.
Push lemon halves inside the chicken’s
cavity – they should all fit if you fiddle
them around. Sit chicken in a smallish
roasting tin, smear butter over the breasts
and season well. Roast, breast-side up,
for 30 mins, then flip over and roast,
breast-side down, for a further 1 hr
30 mins-1 hr 40 mins until the chicken
is cooked through and juices run clear
when you pierce the thigh with a knife.
With 30 mins to go, pour all juices from
the tin into a jug. After juices and fat
separate, spoon 50ml fat from the top
into a big, wide pan. Add the celery, onion
and fennel, and soften gently for 20 mins.
When the chicken is done, pour any
more juices into the jug. Reserve an extra
2 tbsp fat (see Nearly spring greens, related recipes)
and discard remaining fat. On the heat,
stir the flour into the veg until absorbed,
then gradually stir in the stock and chicken roasting juices, simmering
to a sauce. Stir in cream and parsley,
remove from the heat and season.
Shred chicken from the carcass in
large-ish chunks, discarding skin – if the
bird is still hot, use clean rubber gloves
or 2 forks. Juice the roasted lemons,
pick out the seeds and stir all the juices
and roasted pulp into the sauce with
the chicken. Taste and season with a
squeeze more juice from the final lemon
if it needs it. Tip into a large pie dish.
Roll out the pastry on a flour-dusted
surface until big enough to cover the pie.
Brush the rim of the dish with beaten egg
and lift on the pastry. Trim edges, then
press and crimp to seal. Brush all over
with more egg and bake for 30-40 mins
until golden and crisp.