Heat oven to 180C/160C fan/gas 4.
Pat the turkey dry all over with kitchen
paper. Now weigh the bird and calculate
the cooking time at 40 mins per kg. Mix
the butter with the zests and herbs, and
season well. Gently push your fingers
under the turkey’s skin, starting from the
neck end of the bird, easing the skin
away from the flesh over both the
breasts and the tops of the drumsticks.
Spread the butter under the skin, pushing
it in as far as you can, then smooth the
skin back into place. Halve the lemon and
orange and put in the turkey cavity along
with 2 onion halves and the bay leaves.
Rub turkey all over with oil and sprinkle
with salt. Arrange remaining onions in the
bottom of a large roasting tin to act as a
trivet for the bird. Sit the turkey on top and
completely cover both bird and tin with
foil to make a tent. Roast according to
your calculated cooking times.
Thirty mins before the end of the
cooking time, take out the turkey and
turn up the oven to 200C/180C fan/gas 6.
Remove the foil and return to the oven
for a further 30 mins until golden. To test,
pierce the fattest part of the thigh with
a skewer – the juices that run out should
be clear and not pink; keep cooking if
the juices are pink and re-check at 10-min
intervals. If you like your turkey meat
almost falling off the bones, then wiggle
the leg – it should give slightly if the meat
is ready to come away from the bones,
keep cooking and basting until it does.
Rest the turkey, covered loosely with
foil, for at least 30 mins and up to 1 hr
before serving. Strain and reserve the cooking juices and keep the onions in the tin for making gravy (see 'Goes well with', right).