Sprinkle cracked peppercorns and salt evenly over roast; rub in with your fingers. Place roast, fat side up, on a rack in a 15-1/2x10-1/2x2-inch roasting pan. Insert an oven-going meat thermometer into center of roast. Roast, uncovered, in a 350 degree F oven until desired doneness. (Allow 1-3/4 to 2 hours for medium-rare doneness [135 degree F] or 2 to 2-1/2 hours for medium doneness [150 degreeF].)
Reserve pan drippings for Individual Yorkshire Puddings or Yorkshire Pudding. Cover with roast with foil; let stand while preparing pudding(s). (The meat's temperature will rise 10 degree F during standing.)
To serve, slice roast. Serve with the Horseradish Cream. Makes 12 servings.
In a chilled small bowl, beat whipping cream with chilled beater or an electric mixer on medium speed until soft peaks form (tip curl). Fold in cream-style prepared horseradish and dry mustard. Serve immediately, or cover and store horseradish mixture in the refrigerator up to 24 hours.