Position a rack in the lower third of the oven. Preheat the oven to 450°F.
Mix together oil and spices
Rub the mixture over the entire surface of the pork roast
Place the roast directly in a roasting pan. Roast the pork initially for 15 minutes, then reduce the oven temperature to 250°F and roast until a meat thermometer inserted in the thickest part of the meat registers 155 to 160°F, about 80 to 90 minutes more.
Remove the roast to a cutting board, cover loosely with aluminum foil, and let stand for 15 minutes. Skim the fat off the pan juices. If desired, add stock to the pan juices and boil to thicken. Slice the roast and serve with the pan juices or pan sauce.