Preparation

• In a medium bowl, combine the garlic, 1/4 cup of the rosemary, 1/4 cup of the thyme, 1 Tbs. of the oregano, 1 Tbs. kosher salt, and 2 tsp. pepper. Using a sharp, thin-bladed knife, trim the fat cap and silverskin from the roast to expose the meat; also trim any excess fat from the underside.
• Stand the beef on one end, and probe the knife deeply into the ribbons of fat around the muscles to make several deep pockets, making about 5 holes; repeat on the other end of the roast. Stuff some of the herb mixture into these pockets, and rub the rest all over the beef. Put the beef on a rack set in a roasting pan, cover loosely with foil, and refrigerate for at least 4 hours or up to 2 days.
• When you’re ready to cook the roast, position a rack in the center of the oven or use the lower rack, depending on the size and shape of your roast, and heat the oven to 250°F.
• In small bowl, combine the flaky sea salt with the remaining 1 Tbs. rosemary, 1 Tbs. thyme, and 1 Tbs. oregano. Whisk the egg white in a separate bowl until foamy. Use a pastry brush to coat the roast with the egg white. Sprinkle the herb-salt mixture evenly over the top, ends, and sides of the roast.
• Roast the beef until an instant-read thermometer registers 110°F for rare or 115°F for medium rare, 2 to 3 hours. Remove the roast from the oven. At this point, the roast can sit for up to 2 hours before you finish it.
• When you’re almost ready to serve, heat the oven to 500°F. Sear the roast until the exterior is deeply browned and crusty, and the internal temperature is 115°F for rare or 130°F for medium rare, about 10 minutes. Rest for about 20 minutes before carving.