- With the rack in the middle position, preheat the oven to 500°F (260°C). Line a baking sheet with foil.
- In a bowl, combine all of the ingredients, except for the roast.
- On a work surface, rub the roast all over with the seasoning mixture.
- Place the roast on the baking sheet, fat side up. Bake for 25 minutes. Turn the oven off and do not open the door for 2 hours. It is very important not to release any heat from the oven. Remove the roast from the oven and slice. Serve with béarnaise sauce, if desired.
For 6 people: 4 ½-lb (2 kg) roast, cooking time at 500°F (260°C) = 25 minutes
For 10 to 12 people: 8 lb (3.6 kg) roast, cooking time at 500°F (260°C) = 40 minutes
For 14 to 16 people: 11 lb (5 kg) roast, cooking time at 500°F (260°C) = 55 minutes