In a small saucepan, combine the dried cherries, port, and ¼ cup water. Bring to a boil over high heat, then turn the heat to low and simmer for 3 minutes. Set aside to cool.
In a medium skillet, melt 2 tablespoons of the butter over medium heat and add the onion and celery. Sauté for 5 minutes, or until the onion begins to soften, and then add the sausage. Cook, breaking it up with the back of a spoon, until the sausage is browned and cooked completely through. Add the pecans, thyme, and cherries with their cooking liquid. Cook for a few minutes, scraping up the browned bits from the bottom of the pan.
Transfer the mixture to a large bowl and add the stuffing mix, egg, broth, ¾ teaspoon salt, and several grinds of pepper. Stir to combine until the stuffing mix is consistently moistened. Preheat the oven to 375˚F. Place a baking rack over a foil-lined baking sheet.
Unfold the turkey onto a cutting board with the skin side down. Sprinkle with kosher salt and pepper and then spread the stuffing in an even layer, about ½ inch thick, all over the meat, but leaving a small border on each short side so the stuffing doesn’t overflow when it’s rolled up (see note about the extra stuffing).
Starting from a long end, roll the turkey into a tight cylinder. Cut 6-inch lengths of kitchen twine and tie around the turkey at 3-inch intervals to hold it all together. Carefully tuck any stray stuffing back into the turkey roll.
Place the turkey seam side down on the baking rack. Melt the remaining 4 tablespoons of butter and brush it over the turkey. Sprinkle generously with salt, pepper, and herbes de Provence. Roast for 1 hour and then lower the oven temperature to 325˚F and roast for 1 more hour. The turkey is ready when a thermometer inserted into the center registers 150˚F.
Remove the turkey from the oven, cover with foil, and let rest for 10 minutes before carving. Transfer to a platter or cutting board, cut into ¾-inch- thick slices, and garnish with lots of rosemary, thyme, and sage.