Guinness-brined turkey soaks up the robust, toasted flavors of the beer and becomes golden brown in the oven.

Ingredients

• 1/4 cup yellow mustard seeds
• 2 tablespoons black peppercorns
• 8 bay leaves
• 1 cup dark brown sugar
• 1 cup kosher salt
• 2 onions, cut into thick wedges
• 1 pound slab bacon, skin removed and meat sliced 1/3 inch thick
• 6 (12-ounce) bottles guinness stout
• 1 (12- to 14-pound) turkey
• 1 cup turkey stock or lower-sodium chicken broth
• 1 tablespoon unsalted butter
• 1 tablespoon all-purpose flour

Directions

1. In a very large pot, toast the mustard seeds, peppercorns, and bay leaves over moderate heat until fragrant, about 2 minutes. Add the brown sugar and salt, and remove from the heat. Add 4 cups water, and stir until the sugar and salt are dissolved. Let cool completely.
2. Add the onions, bacon, Guinness, and 16 cups cold water to the pot. Add the turkey to the brine, breast side down, and top with a heavy lid to keep it submerged. Cover and refrigerate for 24 hours.
3. Preheat the oven to 350°F with a rack positioned on the bottom position. Lift the turkey from the brine, and remove any peppercorns, mustard seeds, and bay leaves. Pat the turkey dry. Transfer the turkey to a large roasting pan, breast side up. Scatter the onion wedges in the pan, and add 1 cup water. Using toothpicks, secure the bacon slices over the breast. Roast the turkey for about 2 hours, turning the pan occasionally, until an instant-read thermometer inserted deep into the turkey thighs registers 150°F. Remove the turkey from the oven. Remove the bacon from the turkey, and set aside. Return the turkey to the oven. Roast for about 1 hour longer, until the breast is browned and an instant-read thermometer inserted in a thigh registers 170°F. Transfer the turkey to a carving board.
4. Pour the pan juices and onion wedges into a saucepan, and boil until reduced to 3 cups, about 5 minutes. Add the turkey stock, and return to a boil. In a small bowl, mash together the butter and flour into a paste. Whisk the paste into the gravy, and boil until thickened slightly, about 5 minutes.
5. Meanwhile, cut the bacon crosswise into 1/2-inch pieces. In a large skillet, fry the bacon over high heat, stirring occasionally, until browned and crisp, about 3 minutes.
6. Carve the turkey. Serve alongside the onion gravy and bacon.