Season and dry-brine. Pat the roast dry with paper towels. Rub it with a light coat of avocado oil to help the dry rub stick. Season all sides with coarse kosher salt, black pepper, garlic powder, and Tuscan herb rub, if using. Apply all the seasonings together. Refrigerate for at least 3 hours, preferably overnight.
Set up the roasting pan. Preheat the oven to 300°F (150°C). Set the beef on a wire rack in the roasting pan so hot air can circulate underneath and help it cook evenly.
Roast to your preferred doneness. Start checking the thickest part after about 60 minutes. For whole-cut beef, Health Canada lists 145°F (63°C) for medium-rare, 160°F (71°C) for medium, and 170°F (77°C) for well done. Cook until the centre reaches at least 145°F (63°C). The temperature may rise another 7–10°F (4–6°C) as it rests, so keep that in mind when aiming for your preferred finish. The amount varies, so check with your thermometer. Health Canada’s safe cooking temperatures
Rest and chill. Let the roast rest for about 15 minutes. Refrigerate it within 2 hours of cooking and chill it overnight so it firms up for slicing. Public Health Agency of Canada food safety tips
Slice deli-thin. Remove any butcher’s twine. While the roast is cold, slice it across the grain as thinly as you can with a meat slicer or a sharp knife.