Remove giblets from turkey cavity. Wash and rinse turkey inside and out.
In order to determine the right amount of water needed - add the vegetables and aromatics to the stock pot. Stand the turkey up in the pot and fill with enough water to submerge the turkey. Remove the turkey to a platter and allow it to drain and dry.
Bring the water in the stock pot to a boil. The filled pot is going to be heavy so if you can heat it on the burner of a turkey deep frying kit or BBQ side burner consider doing that.
While the water is coming to a boil, pat the turkey dry on the outside. Gently take your fingers and starting at the neck, run them between the breast meat and the skin to separate them. Be careful not to tear the skin. Go as far around the breast and the thigh as you can.
Rub the fat all over the turkey - on the inside between the skin and the meat and on the outside of the skin all over.
Truss the turkey with kitchen twine ensuring legs and wings are well secured. This is important to help you handle the bird later. If you are using a deep frying kit - run the turkey stand through the middle of the bird so it will stand vertically on the stand.
When the water comes to a boil, submerge the turkey vertically in the boiling water. If you are using a deep frying rig you will have a hook tool to help you lift the turkey on the stand.
Allow the water to return to a sier. Cover the pot and simmer for 40 minutes, ensuring the turkey is submerged. After 40 minutes, remove the pot from the heat and allow it to sit to come to room temperature - up to 4 hours.
Refrigerate the turkey and the broth overnight. (You can use the poaching broth in your dressing recipe, gravy recipe to cook other vegetables or reserve for a soup broth.)
An hour or so before you plan to serve it - transfer the turkey from any remaining broth to a rack on a low sided roasting pan.
Preheat the oven to 475°F. Roast the turkey uncovered for 30 minutes. Turn off the oven and allow the turkey to rest in the oven another 20 minutes.
Remove from the oven, carve and serve.