Pre season the roast. The day before cooking the roast, season liberally with coarse salt and wrap with plastic wrap. Store the salted roast in the refrigerator. (optional)
Pre heat the oven to 350 degrees. Remove the roast from the refrigerator an hour before cooking so that it can come to room temperature. Remove the plastic wrap, pat dry with paper towels and season again with coarse salt.
In a cast iron pan, heat 2 tablespoons of the oil over medium high heat. Sear the roast on all sides until a brown crust forms; about 10 minutes.
Combine the remaining oil, butter, parsley, rosemary, thyme, and garlic in a bowl and season with pepper. Rub the herb mixture all over the roast.
Place the silicone roasting racks in a sheet pan and the roast on top of the racks. Cook uncovered for 45 minutes or until thermometer reads 130 degrees for medium rare (roast will continue to cook while resting.)
While the roast is in the oven, whisk all of the ingredients for the horseradish sauce together. Cover and keep chilled until ready to use.
Let the roast rest for 10-15 minutes before slicing thinly.
Serve with horseradish sauce. Enjoy!