Preheat the oven to 325º F. Prepare the dry rub; set aside.
Place the beef into a roasting pan or baking dish. Give it a drizzle of olive oil and then rub the dry rub all over the beef.
Roast the beef in the oven, uncovered, until it’s medium rare with an internal temperature of 145º F. Roasting time will depend on the exact weight of the beef. Roast it for 30 minutes per pound. If your beef is 4 lbs, that’ll be 2 hours in the oven. Use a meat thermometer to check in on the temperature. Be sure to not overcook the beef, or it will be tough, chewy, and lose its overall quality.
When the beef is ready, remove it from the oven and let it rest for 10 minutes before slicing into it so that the juices redistribute.
Creamy Horseradish sauce.
Combine all of the ingredients in a mixing bowl; whisk with a fork until well combined.
*Save the pan juices for leftover beef sandwiches au jus.