- In a large glass or ceramic dish, place the turkey, breast side up.
- In a bowl, combine the garlic and salt. Sprinkle half the salt on the turkey skin. Rub the outside (covered with salt) and the inside of the turkey with the cut side of the lemon for about 2 minutes. Add the remaining salt, particularly to the breast. Cover and refrigerate for 2 days.
- In a food processor, finely chop the leek and carrot. Set aside. Then chop the mushrooms and set aside.
- In a large saucepan over high heat, soften the leek and carrot in the butter. Add the mushrooms and continue cooking until they start to brown. Add the meat and continue cooking until it starts to brown. Add the remaining ingredients. Bring to a boil and simmer over medium-low heat for about 30 minutes or until the mixture is firm and has absorbed most of the liquid. Season with salt and pepper. Refrigerate for 6 hours or until completely chilled.
- With the rack in the lowest position, preheat the oven to 350°F (180°C).
- Rinse the turkey under cold water and pat dry thoroughly with paper towels.
- In a large roasting pan, place the turkey, breast side up. Oil and season with pepper. Stuff the inside of the turkey as well as the neck cavity with the meat mixture. Fold the skin of the neck over the stuffing and tie the legs together with butcher’s twine.
- Roast for 3 hours and 30 minutes or until a thermometer inserted into the thigh, without touching the bone, reads 180°F (82°C). If needed, add 1/2 cup (125 ml) of water to the bottom of the roasting pan halfway through cooking. Set the turkey aside on a large serving platter and keep warm. Degrease and reserve the cooking juices.
- Meanwhile, in a large skillet over high heat, brown the mushrooms and shallots in the butter.
- Deglaze the skillet with the white wine and reduce by half. Add the broth, toasted flour and nutmeg. Bring to a boil, whisking constantly. Simmer over medium heat for about 30 minutes or until the gravy has reduced by half. Add the reserved cooking juices. Season with salt and pepper.
The stuffing and gravy can be made up to 2 days in advance, i.e., at the same time that you prepare the turkey for curing.