Remove the center oven rack and preheat oven to 325 degrees F.

Remove the giblets and neck from the turkey and rinse. Reserve for the dressing.

Place chopped onions, celery, and carrots in the bottom of the roasting pan. Pick a few herbs off the stalks and add to the vegetables. Set aside.

Pat dry the turkey with paper towels. Season the cavity with kosher salt (approximately 2 tablespoons). Place the quartered onion and the remaining herbs inside the turkey cavity. Cover the tips of the wings with aluminum foil and truss the turkey (see Cook's Note**).

Rub the turkey with the softened butter. Place the turkey in the roasting pan breast side up on a roasting rack.

Place the turkey in the oven with the lid on. Baste every hour starting after the first 1 1/2 hours. Cook until an instant read thermometer inserted in the leg meat near the hip joint reads 160 degrees F (approximately 3 hours). Remove the lid and turn the oven up to 400 degrees F. Continue to cook the turkey for 20 to 25 minutes, until the turkey skin is golden and an instant-read thermometer inserted in the leg meat near the hip joint reads 175 degrees F. Remove the turkey from the pan and let it rest in a warm place for 20 minutes before carving (see Cook's Note***.)

Place roasting pan over medium heat and add 1/2 cup of water. Use a wooden spoon to help release the drippings from the bottom of the pan. Using a fine sieve, strain drippings into a medium saucepot. Place the saucepot over medium heat.

Whisk the cream and flour together in a small bowl to create a smooth paste. Add a 1/2 cup of the pan drippings to the cream mixture and whisk together. Pour the cream mixture into the saucepot and whisk together. Cook for approximately 2 to 3 minutes and reduce heat to medium low. Simmer for 15 minutes. Season with salt and pepper. Serve with the perfect turkey.

Cook's Notes: *We found that fresh turkey (one that has never been frozen) is substantially moister after roasting. ** To truss the turkey, securely tie the legs together with a long piece of butcher's string. Use the remaining ends of the string to tie wings snugly to the body of the chicken, then tightly knot the string near the neck to keep the turkey compact. ***Resting meat after the cooking process gives the meat time to redistribute its natural juices and makes it moister.