Step 1

Combine 2 teaspoons kosher salt, whole black peppercorns, sage leaves, garlic, fennel seed, and red pepper flakes in the bowl of a food processors. Process until a rough paste is formed, scraping down sides as necessary, about 30 seconds.

Step 2

Carefully remove skin from the turkey breast and lay it flat. Reserve the carcass for gravy. Using your hands and a boning knife, carefully remove the breast meat from the carcass. Set aside the tenderloins for another use. Follow the slideshow here for step-by-step photos.

Step 3

Lay one breast half on top of the turkey skin and butterfly the thicker end by cutting through it horizontally with a boning knife, leaving the last 1/2 inch intact, then folding out the flap. Repeat with the other breast half. Follow the slideshow here for step-by-step photos.

Step 4

Make a series of parallel slashes at 1-inch intervals in the turkey meat cutting about 1/2 inch into the meat. Repeat with a second series of slashes perpendicular to the first. Rub the spice/herb mixture into the meat, making sure to get it into all of the cracks. Follow the slideshow here for step-by-step photos.

Step 5

Carefully roll of the turkey meat into a tight cylinder, using the skin to completely enclose it. Tie the roast tightly with butcher's twine at 1-inch intervals, as well as once lengthwise. Transfer the roast to a wire rack set in a rimmed baking sheet, cover loosely with plastic wrap, and refrigerate at least 6 hours and up to 2 days. Follow the slideshow here for step-by-step photos.

Step 6

While turkey rests, make the gravy. Roughly chop the carcass with poultry shears or a heavy cleaver. Heat 1 tablespoon canola oil in a large saucepan over high heat until shimmering. Add turkey carcass and cook, stirring occasionally, until well browned, about 8 minutes. Add carrots, celery, and onion, and cook, stirring frequently, until lightly browned, about 5 minutes longer. Add chicken stock, bay leaves, and enough water to barely cover bones. Bring to a boil, reduce to a simmer, and cook for 2 hours. Strain through a fine mesh strainer, discard solids, and spoon any fat off the surface. Return to a saucepan and simmer until reduced to about 3 cups.

Step 7

Melt the butter in a medium saucepan over medium heat. Add flour and cook, stirring with a whisk, until deep golden brown, about 3 minutes. Slowly whisk in turkey broth. Bring to a simmer to thicken lightly, then season with salt and pepper. Let cool and refrigerate until ready to use.

Step 8

When ready to cook, adjust an oven rack to center position and preheat oven to 275°F. Season exterior of turkey lightly with salt and pepper. Heat remaining tablespoon canola oil in a large cast iron or stainless steel skillet over high heat until shimmering. Add turkey and cook, turning occasionally, until well-browned on all sides, about 8 minutes total. Transfer turkey to a wire rack set in a rimmed baking sheet and transfer to oven. Roast until thickest part of turkey registers 145 to 150°F on an instant-read thermometer, about 2 hours. Remove from oven, transfer to cutting board, and let rest for 10 minutes. Meanwhile, reheat gravy. Snip off twine using poultry shears. Carve and serve with hot gravy.