Preheat oven to 350°F. Combine spice rub ingredients in a small bowl. Set aside. Heat corn oil and butter in a large skillet over medium heat. Add celery, onions and 2 tablespoons of spice rub. Cook for 5 to 7 minutes, or until the vegetables are tender but not browned. Add cranberries and apricots; cook 1 to 2 minutes, or until heated through. Transfer to a large bowl. Add bread cubes to cranberry-and-onion mixture and toss. Stir in chicken broth. Rub remaining spice rub on exterior and interior of roast; transfer to a roasting pan. Fill cavity of roast with stuffing. Cover stuffing and rib tips with foil. Place on lower oven rack and bake at 350degreesF for 3-1/2 to 4 hours, or until roast is well browned and internal temperature is at least 155degreesF. Remove from oven and let roast rest for at least 10 minutes. Slice the roast between the bones and serve with stuffing.