Combine the salt, pepper and sage. Place roast, rib ends up, in a large shallow roasting pan; sprinkle with salt mixture. Cover rib ends with foil. Bake, uncovered, at 350° for 1-1/2 hours.
For stuffing, melt butter in a large skillet. Add onion and celery; saute until tender. Transfer to a large bowl; stir in the apples, cranberries, thyme, salt and pepper. Add bread crumbs and toss to coat. Stir in broth.
Carefully spoon stuffing into the center of roast. Bake 45-60 minutes longer or until a meat thermometer reads 145°. Transfer to a warm serving platter. Remove foil. Let roast stand for 15 minutes. Cut between ribs to serve. Yield: 14 servings.