Preheat the oven to maximum. Heat a saucepan until medium hot and add a splash of olive oil, the sage leaves and 6 of the pancetta or bacon strips. Peel and chop 2 garlic cloves and 1 onion. Add the garlic, celery and onion to the saucepan and fry everything gently until soft and golden brown. Take the pan off the heat, add the breadcrumbs and, while the mix is cooling down, chop the apricots roughly and stir them in. When the stuffing has cooled down, add the pork, lemon zest, nutmeg, egg and lots of salt and pepper, and mix everything together well.
Slice the remaining strips of pancetta or bacon in half and slice 1 peeled garlic clove into thin slivers. Place a rosemary sprig and a garlic sliver on one end of a halved strip of pancetta and roll it up tightly. Repeat with the other pieces of pancetta until you have 12 little rolls. Stab the thighs and drumsticks of the turkey in 6 places on each side. Push a little pancetta roll into each hole until it just peeps out. This’ll give your turkey thighs a fantastic flavour and will keep them moist while they cook.
Chop the remaining onions in half and slice the carrots thickly. Give your turkey a good wipe, inside and out, with kitchen paper, and place it on a board, with the neck end towards you. Find the edge of the skin that's covering the turkey's breasts and gently peel it back. Work your fingers and then your hand under the skin, freeing it from the meat. If you're careful you should be able to pull all the skin away from the meat, keeping it attached at the sides. Go slowly and try not to make any holes! Lift the loose skin at the neck end and spoon the stuffing between the skin and the breast, tucking the flap of skin underneath to stop anything leaking out. Pop the orange in the microwave for 30 seconds to warm it up and stuff it into the cavity. Weigh the stuffed turkey and calculate the cooking time (about 20 minutes per 500g/1lb 2oz).
Place the bird on a large roasting tray, rub it all over with olive oil and season well. Surround with the chopped carrots, onions, remaining garlic, cover with tinfoil and place in the preheated oven. Turn the heat down right away to 180°C/350°F/gas 4, and roast for the calculated time, or until the juices run clear from the thigh if you pierce with it a knife or a skewer. Remove the tinfoil for the last 45 minutes to brown the bird. Carefully lift the turkey out of the tray and rest on a board that’s covered loosely with foil for at least 1 hour, preferably 2 hours for bigger birds. When the resting time's nearly up, skim the surface fat from the roasting tray and add the flour and stock. Place the tray on the hob and bring to the boil on a high heat. When the gravy starts to thicken, strain it into a bowl. Carve your turkey, serve with the gravy and dig in!