With the rack in the middle position, preheat the oven to 180 °C (350 °F). In a bowl, combine spices, salt and Cayenne pepper. Coat roast with spice mixture.
In a large ovenproof skillet, brown the onions in the oil. Season with salt and pepper. Place the meat in a roasting pan and roast for about 1 hour or until a thermometer inserted in the centre of the roast reads 135 °F (57 °C). Transfer the roast to a platter, cover with aluminium foil and let rest until the thermometer reads 145 °F (63 °C). Keep the onions warm.
1 rack of pork, about 3 lbs (1.4 kg)
2 teaspoons (10 ml) paprika