Brined spatchcocked roast turkey, two halves cooked to different temperatures

Spatchcock the turkey: cut up both sides of the backbone with scissors and keep the backbone for stock.

Remove the breastbone, save it for stock, and cut the turkey into two halves.

Make a brine of salt and water, no more than 5% salt by weight of the water, nearer 3% for less salty meat, with no more than half as much sugar as salt.

Brine the halves overnight, kept cold with sealable ice packs (never loose ice, which dilutes the brine) at refrigerator temperature, about 40F / 4C; otherwise brine in the refrigerator.

Next day, take the halves out and dry them off a little.

Season both sides heavily with pepper, dried thyme, sage, garlic powder and onion powder, no salt; rub with a little oil or clarified butter.

Cover the breast with foil to slow its cooking.

Roast at about 350F convection; about 90 minutes total.

After the first hour or so, remove the foil and turn the heat up to about 400F / 200C or higher to brown the skin.

Take the first half out when the breast is almost 160F / 71C; it rises to the recommended temperature as it rests.

Give the second half 10 to 20 more minutes, to a breast temperature of about 175F / 79C.

Separate the dark meat from the white and carve the breast of each half.

For gravy, brown a little flour in the drippings, deglaze with water rather than salty stock, and season; cut it with extra unbrined stock made from the backbone because the brined drippings are very salty.