Preheat oven to 425F. Equipment: 1 roasting pan, butcher’s twine
Scatter onions, celery, carrots, garlic, herbs, orange, and dried mushrooms in the bottom of a roasting pan. Add white wine. If using a V-rack for the turkey, position the rack in the pan. If you do not use a rack, the vegetables will keep the turkey from becoming too wet from lying in its juices and will add flavor to pan juices.
Remove neck and giblets from turkey.
Rub turkey with butter or olive oil. Mix salt, pepper, stuffing seasoning, and Herbes de Provence together. Rub seasoning all over turkey including inside. Place orange, garlic and fresh herbs inside turkey cavity and tie legs together. Tuck wings under the bird and place the bird either in V-rack or on top of vegetables. Add neck to the roasting pan and place giblets with vegetables.
Roast turkey for 20 minutes, decrease oven temperature to 325F and continue roasting, If the breast starts to darken too quickly, cover with a piece of foil and continue basting with pan juices every 30 minutes until thermometer inserted in the thickest part of the thigh registers 155F (about 3-3 ½ hours) (turkey is considered safe to eat when the temperature is 165F), the temperature will continue to rise as the turkey rests.
Remove the turkey from the pan and lightly tent with foil. Strain vegetables from pan juices and transfer pan juices to a saucepan. Allow to cool.
Cut up giblets and pull meat from roasted neck.
Strain off fat from pan juices. (save the fat to use for gravy or roasting potatoes). For a natural pan jus, reduce pan juices until they thicken slightly or make Porcini Gravy.
Add 4 tablespoons of strained poultry fat to a pan over medium heat. Whisk 4 tablespoons of flour into the fat until thoroughly combined.
Add ½ cup of dry white wine and turkey pan juices and enough poultry stock to equal 3 cups of liquid. Reduce heat to simmer. Add TSH dried porcini mushrooms, add celery with herbs, add cut giblets and neck meat, and simmer, stirring occasionally for 15 minutes.
Remove celery and adjust seasoning with salt and pepper. Serve gravy with sliced turkey.