Refrigerate the turkey in the refrigerator at 38 F, two to three days before roasting the turkey.

In a large stockpot over medium-high heat, pour vegetable stock, add black peppercorns, brown sugar, candied ginger, salt, and allspice berries.

Stir occasionally and bring the mixture to a boil. Remove from the heat and let it cool. Then, refrigerate it until required.

A night before roasting the turkey, take it out from the fridge.

In a 5-gallon bucket, combine water with prepared brine and ice.

Immerse the thawed turkey in this brine, cover it and refrigerate it for about 8 hours, turning this bird halfway throughout brining.

Then remove the turkey from the brine, rinse it, and pat it dry.

In a microwave-safe bowl, add apple slices, chopped onion, oil, a cup of water, and a cinnamon stick. Microwave it for about 5 minutes.

Transfer these aromatics into the turkey cavity along with rosemary sprigs and sage in it.

Roast the turkey for about 30 minutes in a preheated oven (300 F) until brown, crispy, thickened.

Reduce the temperature to 350 F and roast it for another 2 to 2.5 hours.

Let the turkey rest (wrapped in foil) for about 15 minutes before carving.