To make brine solution, dissolve salt and sugar in 2 gallons of cold water in a nonreactive container, such as a clean bucket or large stockpot, or a clean, heavy-duty, plastic garbage bag. Add lemons, thyme, rosemary, and juniper. (Double the recipe if using a larger bird.)

Rinse turkey inside and out under cold running water. Soak turkey in brine, covered and refrigerated, for at least 4 hours and up to 24 hours.

In a food processor, combine lemon zest, garlic, chipotle peppers, cumin, and sunflower oil. Process into a paste.

Remove turkey from refrigerator 1 hour before cooking. Preheat oven to 325°. Remove turkey from brine and rinse well under cold running water. Pat dry. Place in a large, heavy roasting pan, and rub on all sides with canola oil. Roast turkey for 1 hour. Remove from oven and baste with pan juices or stock.

Gently loosen turkey breast skin with hands. Rub lemon-chipotle mixture under and over turkey skin. Return turkey to oven and continue roasting until an instant-read meat thermometer registers 165° when inserted into the largest section of thigh (avoiding the bone), about 2 3/4–3 hours total cooking time. Check to see if breast is browning too quickly; cover with aluminum foil if needed. Baste turkey once every hour with pan juices or stock if desired.

Remove from the oven and place on a platter. Let rest for 20 minutes before carving.

While turkey is resting, make gravy: Pour juices from pan into a measuring cup and deglaze pan with wine. In a small pan, melt butter. Whisk in flour and chipotle; cook for 2 minutes. Whisk in 3 cups stock for about 1 minute. Skim fat from measuring cup, add white wine mixture, and add to pot. Stir until smooth and starting to thicken. Add more stock if needed.