1 Tbsp. drained prepared horseradish from a jar, squeezed dry
Preheat oven to 350 degrees. Place beef in roasting pan. Sprinkle top and sides with rosemary, salt, and pepper. Roast until meat thermometer into thickest part of beef registers 135 degrees for medium rare, about 1 hour, 15 minutes. Combine next 4 ingredients; brush over roast during last 10 minutes of cooking time. Let stand 10 minutes before slicing.