Brine the turkey in the fridge for24 hours, this process will tenderize and give your bird a wonderful citrus flavour base. Pat dry your turkey thoroughly with a paper towel.
In a small bowl, prepare the marinade by combining olive oil, 7-spice powder, salt, black pepper powder, white pepper powder, cinnamon powder and nutmeg. Rub the mix all over the turkey to thoroughly season the bird.
Using your fingers, slowly peel the skin covering the turkey’s breast and spoon the butter between the skin and breast. Stuff the stomach of the turkey with 1 orange,1 bay leaf, 4 sprigs of rosemary, some chopped celery, carrots and onions, and garlic bulbs.
Preheat the oven to the maximum temperature (220°C). Place the turkey on a large roasting tray. Surround with the remaining chopped celery, carrots, onions, garlic, rosemary, remaining giblets and neck, and two cups of water or chicken stock.
In a small pan melt butter and gently submerge a muslin cloth, large enough to cover the whole turkey. Submerge the muslin cloth in the melted butter, ensuring it's completely soaked. Drape the butter-soaked muslin cloth over the entire turkey. This helps keep the bird moist and tender while creating beautifully browned skin.
Place theroasting pan in the oven on the lowest rack and roast at maximum heat for 20 minutes. Then reduce the temperature to 160°C, continueroasting for about 3 hours, andbaste the bird every 20–30 minutes toensure the meat does not dry.
When the turkey is cooked, remove it from the roasting pan onto a serving plate, cover it with tin foil and allow it to rest for 20 to 30 minutes before serving.
To make the gravy, strain the liquid into a measuring cup and place in the fridge for 30 minutes. This process will allow the fat to separate and harden, making it easier to skim off the fat.
In a small saucepan, melt ¼ cup of the butter on medium–high heat, add the flour and whisk until light brown to make a roux. Add the turkey stock. Whisk ingredients until sauce thickens. Add a bit more chicken stock if you want the gravy to be thinner. Season with salt and pepper.
Serve the turkey with gravy and serve it with your favorite side dishes.