The best roast beef cannot be rushed. The most common cut for use in making a roast beef (not a pot roast, which is a totally different thing) is eye of round. It's a very lean cut of beef, which means anything but a long, low cooking process will produce a dry, tough roast. Use this recipe for the best, most flavorful roast beef. This method is inspired by America's Test Kitchen's low-and-slow technique.
For the best, sliceable roast beef, choose an eye of round roast. This recipe will work for anything between 3 1/2 to 4 1/2 lb roast.
Rub the salt over the surface of the beef and wrap tightly in plastic wrap. Store in the refrigerator for at least 12, preferably 24 hours.
Preheat oven to 225°F. Dry the surface of the beef with paper towels, then rub with the vegetable oil. Season with pepper. Heat a frying pan with oil until it's very hot, then sear ALL SIDES of the roast. You can hold the ends up with a pair of tongs. It should take about 10 minutes to get a good, hard sear on the meat.
Place the beef on a wire rack, set inside a baking pan - you want it elevated out of any juices.
Roast the meat in the 225°F oven for about 1 1/2 hours, then take an internal temperature with a meat thermometer. Turn the oven off when it reaches 115°F for medium-rare, or 125°F for medium. Don't go any higher, as this particular cut will be very tough beyond a medium roast.
Once it reaches your desired temperature, turn the oven off, but leave the roast in the oven for another 40 minutes.
Transfer the meat to a cutting board to rest for 10 minutes before carving. Carve very thin slices and serve with horseradish sauce.
Horseradish Sauce
Whisk cream until thickened, but not forming peaks. Fold in remaining ingredients. Refrigerate for 30 minutes before serving.
Notes
Eye of round is a cut that is very low in fat, so overcooking will result in a very tough piece of meat. Medium is the maximum cook for this roast beef.Salting overnight not only adds flavor, but breaks down the proteins a bit, for a tender cut.When roasting at such a low temperature, you won't generate a lot of browning. The only browning will be from your initial sear, so sear it until you get the nice fully-browned roast you want to serve.It's important to keep the oven door closed as much as possible. When taking an internal temp, remove the roast from the oven completely, keeping the door closed as much as you can.