Tie the pork tightly with twine at ¾- to 1-inch intervals to make the roll as perfectly round as possible.
Combine the dry brine ingredients, rub evenly over the entire roast and leave uncovered in refrigerator 24 hours on lowest rack.
Take the pork out of the refrigerator 30 to 45 minutes before roasting.
Preheat oven to 425°F, with rack at center.
Fill a roasting pan with apples, pears and onions and season with a little salt and pepper. Pour the Calvados and stock over the apples, pears and onions.
Rachael Ray 16.5" x 13.5" Nonstick Roaster with Reversible Rack
Rachael Ray 16.5" x 13.5" Nonstick Roaster with Reversible Rack
Place a rack over the top and set the pork roast on it. Coat lightly with EVOO spray and place in oven.
Roast pork 30 minutes at 425°F, then reduce heat to 325°F and roast to 140°F, about 45 minutes more. Remove and let stand 15 to 20 minutes before carving.
If making gravy, melt butter in a saucepan over medium heat, whisk in flour, then add salt and pepper. Whisk in stock and bring to a boil to thicken enough to coat a spoon. Add cream and temper an egg yolk (if using) by whisking together yolk and a ladle of gravy, then adding yolk mixture back to sauce. Whisk in Dijon mustard (if using).
Remove strings from the pork roast and thinly slice. Serve with roasted fruit and onions and top with pan juices or gravy.
