For a lighter version, substitute olive oil for the butter, and replace the heavy cream with either milk or half-and-half. If you don't want to use sherry, add 2 additional tablespoons of broth.
In a large saucepan of boiling salted water, cook broccoli about 5 minutes, or until tender; drain. Butter a 9 x 13 x 2-inch baking dish; arrange broccoli across the bottom. Top with turkey; cover with foil to keep warm.
In a large skillet, melt butter over medium heat. Sauté onions and mushrooms until golden brown (add a little broth if mixture seems dry). Add flour, and cook, stirring, 1 minute. Stir in broth; bring to a boil. Reduce heat to low; simmer 3 to 5 minutes, or until thick. Stir in sherry; cook 1 minute. Add cream and 1/4 cup Parmesan; simmer 1 minute. Season to taste with salt and freshly ground black pepper. Remove from heat.
Meanwhile, arrange a rack 6 inches below the heat source, and preheat the broiler to high. Pour sauce over turkey. Top with the remaining 1/4 cup Parmesan and almonds. Broil for 1 minute, or until the sauce bubbles and the almonds are golden brown.
1 Defrost and De-Chill
If you are starting with a frozen turkey, you will need to defrost it first, a process that can take several days depending on the size of the turkey. Place the wrapped frozen turkey in a pan to catch any leaks, and then in the refrigerator to defrost. You will need about 5 hours of defrosting for every pound of turkey. Which means that if you have a 15 pound turkey, it should take 75 hours, or a little over 3 days, to defrost.
Remove the turkey from the refrigerator 2 to 3 hours (depending on the size of the bird) before cooking to allow it to come closer to room temperature. The turkey will cook more quickly and more evenly that way.
2 Remove Giblets and Rinse Turkey
When you are ready to cook the turkey, remove it from its package. Reach into the turkey's main cavity and pull out the neck and giblets (gizzard, heart, liver). The giblets may be wrapped in a small paper package. (If they're not in the main cavity, check the neck opening, sometimes they're hiding there!) If you want, you can chop up the heart and gizzard to make stock for the stuffing or dressing (put the chopped heart and gizzard into a small saucepan, cover with water, add salt, bring to simmer for an hour or so.) You can either cook the neck alongside the turkey, or save it for turkey soup. You can also use all of the giblets for making giblet gravy.
Rinse the turkey inside and out with water. If you see any remnants of turkey feathers, pull them out. Use paper towels to pat dry the turkey.
Many turkeys come with a plastic tie holding the drumsticks together. Check the instructions on the turkey package; it is likely that you will not need to remove the tie unless you are cooking the turkey at a very high temperature. If you do remove the plastic tie, and you may want to truss the turkey with kitchen twine to help hold the legs together.
3 Preheat the oven to 400 degrees F.
4 Insert Aromatics and Truss Turkey
Slather the inside of the cavity with the juice of half a lemon. Take a tablespoon of salt and rub all over the inside of the turkey.
Put half an onion cut into wedges, several sprigs of parsley, a couple of carrots, and some celery tops and bottoms into the main cavity of the turkey. These are aromatics that will flavor the turkey from the inside as it cooks. Cover the entrance to the main cavity with aluminum foil, or close it with metal skewers or kitchen string (not nylon string!), so that the aromatics don't fall out.
By the way, we don't cook stuffing in the turkey anymore. Stuffing the turkey adds to the overall cooking time, and not packing the turkey with stuffing will allow the turkey to cook more evenly. We do make our stuffing with stock made from the turkey giblets so the stuffing has plenty of turkey flavor.
To truss or not to truss? We truss our turkey, though some people choose not too. The point of trussing is to keep the legs and wings close to the body so they don't spread out while cooking. To truss, make sure that the turkey's legs are tied together, held close to the body, and tie a string around the turkey body to hold the wings in close. (Here's a good video on trussing: how to truss a turkey.)
Put a few sprigs of parsley into the neck opening, cover the opening with the surrounding turkey skin, and close the opening with skewers or string.
5 Rub with Olive Oil or Butter, Salt and Pepper
Rub either softened butter or olive oil all over the outside of the turkey. Sprinkle salt generously on all sides of the outside of the turkey (skip added salt if you are using a brined turkey). Sprinkle pepper over the turkey as well.
6 Place Turkey Breast Down on Rack
Place the turkey BREAST DOWN on a rack over a sturdy roasting pan big enough to catch all the drippings.
This is main difference between how my mother makes her turkey and everyone else. By cooking the turkey breast side down, the juices from the cooking turkey fall into the breast while the turkey cooks, resulting in them most succulent breast imaginable. The thighs are a bit more exposed to the heat in this method as well, which is good since dark meat takes longer to cook than white meat.
If you cook the bird breast down, the turkey skin over the breast will not brown well. If you want browning on the breast, you'll need to turn the turkey over in the pan and to brown it in the last few minutes of cooking. We rarely bother with turning the turkey over, since we carve up the turkey in the kitchen before bringing it out, and there is plenty of crispy turkey skin on the rest of the turkey.
Note that you can also place the turkey directly on an oven rack with a large roasting pan to catch the drippings on the rack below. That method helps create a convection-like environment, helping the heat circulate more evenly around the turkey.
Add several sprigs of fresh (if possible) thyme and rosemary to the outside of the turkey or tucked under the wings.
7 Roast the Turkey
Before you put the turkey in the oven, do a rough calculation of how much overall time it should take to cook the turkey. Usually they say to assume 15 minutes for every pound of meat, but I have found in practice that it's usually less than that, more like 13-14 minutes per pound. Cooking time will vary depending on the size of the turkey, if it has been allowed to come to room temperature before cooking, and the shape and particulars of your specific oven. So come up with a rough estimate for the overall cooking time, and then make sure to check how the turkey is doing well before it is supposed to be done!
Put the turkey in the oven at 400°F, uncovered. For the 15 lb turkey, start the cooking at 400°F for the first 20 minutes to brown it. Then reduce the heat to 325°F for the next 2 hours. Then reduce the heat further to 225°F until done, anywhere from a half hour to an hour or more.
If you want the breast to be browned, when the turkey is close to being done, you'll need to turn the turkey over so that the breast is on top, and put it in a 500°F oven or under the broiler for 4 to 5 minutes, just enough time to brown the breast. Note that by browning the breast you may end up over-cooking the turkey breast a bit. We usually don't turn the turkey over. Also, turning it over can be a hot, messy job, so if you do it, take care and use oven mitts or clean kitchen towels.
Start taking temperature readings with a meat thermometer, inserted deep into the thickest part of the turkey breast and thigh, an hour and a half before the turkey should be done. You want a resulting temperature of 170°F for the dark meat (thighs and legs) and 165°F for the white meat (breast). The temperature of the bird will continue to rise once you take it out of the oven, so take it out when the temperature reading for the thigh is 165°F, and for the breast 160°F. If you don't have a meat thermometer, spear the breast with a knife. The turkey juices should be clear, not pink.
The USDA recently lowered its recommended cooking temperatures for poultry to 165°F. I've found that at that temperature often the thigh meat near the bone still isn't cooked, so I aim for 170°F for the thighs.
8 Let Turkey Rest, Then Carve
Once you remove the turkey from the oven, transfer it to a cutting board, tent it with aluminum foil to keep it warm, and let it rest for 15-30 minutes, depending on the size of the turkey. Turn the turkey breast side up to carve it. (See Alton Brown video on how to carve a turkey.)