1. Preheat oven to 325°F. Check the wrapper to see how much the turkey weighs and determine approximate cooking time (see chart below). Remove the giblet bag and the neck from the turkey cavity. Wash the turkey inside and out and pat skin dry with paper towels.
2. Place turkey breast side up on a rack in a shallow (about 2 inches deep) roasting pan. Insert meat thermometer in thigh. Add 1/2 cup water to the bottom of pan, if desired.
3. Cover turkey loosely with a tent of heavy-duty aluminum foil. Roast the turkey until temperature in the innermost part of the thigh reaches 165°F as measured with a food thermometer. Check the wing and the thickest part of the breast. You may choose to cook the turkey to higher temperatures. Cooking time will vary. For example, a 20 pound turkey will take 4 1/4 to 5 hours to cook, check the temperature on the thermometer after 4 1/4 hours.
4. Meanwhile, mix the stuffing or dressing. Place in a casserole and pop it into the oven during the last hour or so of roasting time.
5. Remove the foil tent after 1 to 1 1/2 hours of cooking time to brown the skin. Brush with vegetable oil to enhance browning, if desired.
6. A whole turkey (and turkey parts) is safe when cooked to a minimum internal temperature of 165 °F as measured with a food thermometer. Check the internal temperature in the innermost part of the thigh and wing and the thickest part of the breast. For reasons of personal preference, consumers may choose to cook turkey to higher temperatures.
7. Allow the turkey to set 20 to 30 minutes before carving to allow juices to saturate the meat evenly.
Cooking time is the endless issue about cooking roasted turkey. Luckily, I've found a pretty good site in which
Turkey Farmers of Canada, made an elaborate chart with the best recommendations for cooking a whole turkey and concluded that the best way is to do it to an internal temperature of 170°F (77°C) in the breast and 180°F (82°C) in the thigh.
When roasting, any stuffing placed in the cavity of the bird should reach an internal temperature of at least 165°F (74°C).
Let the bird stand for 15 to 20 minutes before carving.