Herb Roasted Turkey with Gravy

Description
"I wasn't always a briner," says Shawn McClain, "but when enough people tell you it's the thing to do, you try it." He's glad he did: The brine here, which is a simple combination of salt, sugar, spices and water, keeps the turkey moist in the oven and seasons the meat perfectly.
Ingredients
- 2 tablespoons fennel seeds
- 2 tablespoons mustard seeds
- 2 tablespoons coriander seeds
- 6 bay leaves
- 1 1/2 cups kosher salt
- 1 cup sugar
- 8 quarts cold water
- 1 (18-pound) turkey
- 2 sticks plus 2 tablespoons unsalted butter, softened
- 3 tablespoons chopped flat-leaf parsley
- 1 tablespoon chopped sage leaves
- 1 tablespoon chopped thyme leaves
- freshly ground pepper
- 2 tablespoons all-purpose flour
- 3 quarts chicken stock or low-sodium broth
- 1/2 small onion, finely chopped
- 1 small carrot, finely chopped
- 1 celery rib, finely chopped
- 1 cup diced peasant bread
Directions
- In a large saucepan, combine the fennel, mustard and coriander seeds with the bay leaves, salt, sugar and 1 quart of the water. Bring to a boil, stirring to dissolve the salt and sugar. Transfer the mixture to a very large bowl or pot and add the remaining 7 quarts of cold water. Add the turkey, breast side down. Cover and refrigerate for at least 8 hours or overnight.
- Preheat the oven to 450°. Drain and rinse the turkey and pat dry; discard the brine. Starting at the neck end of the bird, slip your hand between the skin and meat to loosen the turkey skin.
- In a medium bowl, combine the 2 sticks of butter with the parsley, sage and thyme and season with pepper. Spoon 1/4 cup of the herb butter into a small bowl and stir in the flour; cover and chill. Spread the remaining herb butter all over and under the skin of the turkey and set it on a rack in a roasting pan. Add 2 cups of the stock to the pan and roast for 30 minutes. Lower the oven temperature to 325° and roast the turkey for about 2 1/2 hours longer, basting occasionally; the turkey is done when an instant-read thermometer inserted in the thigh registers 170°. Transfer the turkey to a cutting board and let rest for 30 minutes.
- Meanwhile, in a large saucepan, melt the remaining 2 tablespoons of butter. Add the onion, carrot and celery and cook over moderate heat, stirring occasionally, until softened, about 5 minutes. Stir in the bread and cook for 1 minute. Add 2 quarts of the stock and bring to a boil. Simmer over moderate heat until the liquid is reduced to 3 cups, about 1 hour and 15 minutes. Whisk to break up the bread. Strain the stock through a fine sieve and return it to the saucepan. Whisk in the chilled reserved herb butter and bring the gravy to a boil. Cook, whisking, until thickened, about 5 minutes.
- Pour off the fat from the roasting pan and place the pan over high heat. Add the remaining 2 cups of chicken stock and cook, scraping up any browned bits stuck to the pan, until boiling. Strain the pan drippings into the gravy and season with salt and pepper.
- Carve the turkey and serve on a platter, passing the gravy at the table.