1. Preheat the oven to 375°F. While you wait, mix the spices and salt to make a spice rub. Rub the olive oil over the pork loin, and rub in the dry spice mix all over with your fingers.
2. Set the rack over the roasting pan, stick a meat thermometer probe in the thickest part of the roast, and place it in the oven.
3. Cook the pork for 45 to 60 minutes, or until the internal temperature hits between 145 to 160°F. Once done, set down, cover loosely with foil, and let it sit for 20 minutes before serving.

You can also check out this video on how to make juicy pork roasts in the oven.