1. Place the oven rack in the middle position and preheat the oven to 250°F.
2. Combine all spices and seasonings together in a small bowl.
3. Rub the roast all over with a tbsp of oil before rubbing in the spice mixture.
4. Heat the remaining oil in a large cast iron skillet over medium-high heat.
5. Add the roast and sear until browned on all sides, about 3 minutes per side.
6. Transfer the roast to a wire rack set inside a roasting pan.
7. Cook for 1 hour and 20 minutes, or until the meat reaches 115°F on a meat thermometer.
8. Turn the oven off, leaving the roast in the oven for another 40 minutes, or until the roast reaches an internal temperature of 130°F for medium-rare or 140°F for medium.
9. Remove the roast from the oven to a carving board, and cover loosely with aluminium foil and allow to rest for at least 15 minutes before carving.
10. Slice the meat to desired thickness and serve.