Prime Rib with Horseradish Sauce

1 semi-boneless beef rib roast (4 to 6 pounds)
1 tablespoon olive oil
1 to 2 teaspoons coarsely ground pepper

Horseradish Sauce
1 cup (8 ounces) sour cream
3 to 4 tablespoons prepared horseradish
1 teaspoon coarsely ground pepper
1/8 teaspoon Worcestershire sauce

Brush roast with oil; rub with pepper. Place roast, fat side up, in a shallow roasting pan. Bake, uncovered, at 450° for 15 minutes.

Reduce heat to 325°. Bake for 2-3/4 hours or until meat reaches desired doneness (for medium-rare, a meat thermometer should read 145°; medium, 160°; well-done, 170°), basting with pan drippings every 30 minutes.

Let stand for 10-15 minutes before slicing. Meanwhile, in a small bowl, combine the sauce ingredients. Serve with beef. Makes 6-8 servings.