Get your turkey and use a spoon to work your way between the skin and the meat. Start at the side of the cavity just above the leg and work gently up towards the breastbone and towards the back so you create a large cavity. Pick up half of your butter and push it into the cavity you've created. Use your hands to push it through the skin right to the back so it coats the breast meat as evenly as possible. Do the same on the other side then rub coconut oil all over the outside of the bird to use it up. If you've got any herb stalks left over, put them in the cavity of the turkey for added flavor as it cooks.
Cover the turkey in cling film and keep in the fridge until you need it.
Take your turkey out of the fridge a few hours before you are ready to put it in the oven so it has time to come up to room temperature. Halve the clementines and pop them in the cavity with a few more sprigs of fresh herbs like rosemary, bay and thyme. The fruit will steam and flavor the birds in a really lovely way. Take the fresh rosemary, pull off the leaves at the bottom then spear that through the loose skin around the cavity to hold it together and keep it from shrinking back as the turkey cooks.
Open up the neck cavity and pack as much stuffing as possible in there, then carefully pull the skin back over the cavity, tuck it under the bird and pop it in the roasting tray. If you've already made your gravy like I've done, you won't need a vegetable trivet, if not, do that now by roughly chopping the carrots, onions and celery sticks. Preheat your oven to full whack, get the turkey in the roasting tray and cover with foil. As soon as it goes in the oven, immediately turn the heat down to 180ºC/350ºF/gas 4.
As a rough guide, you want to cook the turkey for about 35 to 40 minutes per kilogram, so a 7 kg turkey will want about 4 to 4½ hours in the oven.Check on your turkey every 30 minutes or so and keep it from drying out by basting it with the lovely juices from the bottom of the pan. After 3½ hours, remove the foil so the skin gets golden and crispy. If you are at all worried just stick a meat thermometer in the thickest part of the breast. When the internal temperature has reached 65ºC for a good quality bird, and about 82ºC for a cheaper bird, it's ready to come out.
Carefully put a metal skewer in the cavity and use it to lift the bird and angle it over the roasting tray so all of the juices from the cavity run out. Move the turkey to a platter then cover it with a double layer of tinfoil and 2 tea towels to keep it warm while it rests for at least 30 minutes.