To roast the turkey

1. Preheat the oven to 400º F and move the oven rack to the center (or low enough to fit your pan).
2. Mash the butter, salt, pepper, and minced rosemary into a paste (a mortar and pestle works great, or you can smash it with the back of a spoon or knife).
3. Place the turkey in the pan on a roasting rack, and pat it dry with paper towels. Rub it all over with the butter, including under the skin. Don’t layer it too thick on the skin, or it won’t brown.
4. Lay half of the rosemary and thyme over the turkey, and half under it. Place the garlic bulb and the shallot in the pan as well.
5. Squeeze one half of the orange over the turkey, then place the rind in the pan, setting the other half aside for later. Pour the wine over the turkey as well.
6. Bake, uncovered, for 45 minutes or until it reaches 155-160º F on a meat thermometer.
7. Cover with foil and allow it to rest at least 10 minutes, or until it reaches 165º F. 
8. Slice the meat off the bone and slice the breast into serving portions. Garnish with orange slices. 

To make the gravy

1. Melt the butter in a small saucepan, and add the chicken stock and strained turkey drippings. Bring to a boil over medium heat, turn down to low and simmer for about five minutes.
2. In a small bowl, mix the cornstarch with two teaspoons of cold water until dissolved.
3. Pour the cornstarch slurry into the liquid, turn down the heat, and whisk until it’s thick enough to coat the back of a spoon. 
4. Serve immediately or keep warm until serving.