Preheat the oven to 400°F
Pat the pork loin dry with paper towels
Rub the pork loin with oil
Season all sides with salt, pepper, and any desired spices
Place the pork loin in a roasting pan or oven-safe skillet
Insert a meat thermometer into the thickest part if available
Roast for about 20 to 25 minutes per pound
Check for an internal temperature of 145°F
Remove the pork loin from the oven
Let it rest for 10 to 15 minutes before slicing
Slice and serve