Dry-brine your turkey one day before cooking. Liberally sprinkle its back (including legs and wings) with salt, then leave it in a tray, back side up and uncovered, in the fridge for 4 to 6 hours. After that, pat the bird dry with some paper towel and lay it in a fresh tray, breast-side up. Sprinkle it again with salt, then put it back in the fridge overnight. Pull the turkey out of the fridge 30 minutes before cooking.

Preheat your oven to 325 F. Combine the mayo rub ingredients and massage it over the entire bird. Stuff the lemon, garlic, and thyme sprigs loosely into the bird's cavity, then truss the legs together. Position the turkey in a rack, then put that in a roasting tray. Put the bird in the oven for 2 hours.

Combine the apple cider vinegar with an equal amount of cold water. Pull the turkey out of the oven and baste it with the vinegar solution (this will help dry out the skin). Put the turkey back in the oven until it reaches an internal temperature of 165 F in both the thigh and the breast). This should take between 1 3/4 to 2 1/4 hrs. Pull the turkey out and let it rest at least 30 minutes before carving.

Add the butter to a small saucepan on medium heat. Once melted, add the shallot and let cook for 15 minutes until the shallots are really softened. Stir in the tomato paste and keep cooking until the paste almost dries out, about 6 to 8 minutes. Add the soy sauce. Carefully, off the heat, pour in the cognac and let simmer until most of the liquid has evaporated.

Add the garlic powder, onion powder and dried thyme. Let cook a minute until fragrant, then pour in the stock. Stir in the gelatin (this will add the silky mouthfeel you expect from gravy). Bring to a boil and let reduce by half. Season with freshly cracked black pepper and salt if required. Make a slurry by combining the cornstarch with 1/4 cup water, then whisk it into the saucepan. Let simmer a final 2 or 3 minutes, then serve.