Preheat your oven to 350°F (175°C). Remove giblets and neck from the turkey and rinse under cold water. Pat dry and season inside and outside with salt and pepper.

Melt butter in a skillet over medium heat. Sauté diced onions and celery until softened, about 5-7 minutes. Toast bread, cube it, and transfer to a bowl. Combine sautéed mixture with bread, then add Stove Top Stuffing mix and seasonings, moistening with chicken broth until damp.

Stuff the turkey cavity with prepared stuffing. Secure openings with skewers or kitchen string.

Place the stuffed turkey in a roasting pan, rub with butter and season with salt and pepper. Tent with foil and roast for about 3.5 hours, basting every 30 minutes. Remove foil for the last 30 minutes to brown the skin.

Use a meat thermometer to check the internal temperature; it should read at least 180°F (82°C) in the thigh and 165°F (74°C) in the stuffing. Continue roasting if necessary.

After roasting, let turkey rest for about 20 minutes. Collect drippings in a fat separator. Pour chicken broth into pan, scraping up browned bits. Whisk flour with cold broth until smooth, then add to drippings and simmer until thickened.

Carve the turkey and serve with stuffing and gravy.