1. Preheat oven to 500°. Combine first 6 ingredients in a small bowl; rub mixture over beef. Place beef in a large pan.
2. Bake at 500° for 10 minutes. Reduce oven temperature to 350°. Bake for 30 more minutes or until a meat thermometer registers 140° or until desired degree of doneness. Remove from oven, and cool until room temperature (1 hour).
3. Meanwhile, prepare Creamy Horseradish Sauce.
4. Wrap beef in plastic wrap; chill overnight. Cut roast into 1/2-inch slices; arrange slices on a serving platter. Garnish, if desired. Serve with Creamy Horseradish Sauce.