Preheat the oven to 350°F.

Cover a roasting rack with a sheet of aluminum foil and poke small holes all over with the tip of a sharp knife. Line a roasting pan with heavy-duty aluminum foil and position the roasting rack inside of it.

Pat the pork loin dry with paper towels, and rub with olive oil. Season the pork loin liberally on all sides with salt and black pepper. Use the back of a spoon to spread the mustard in an even layer over the surface of the meat.

Place the sauerkraut in an even layer on the foil-covered roasting rack, and center the pork loin on top. Sprinkle the caraway seeds over the pork and sauerkraut.

Roast the pork loin on middle rack of oven until the meat reaches an internal temperature of 138-142°F, 75-90 minutes.

Check to see that pork loin is done. Remove from oven or add time as needed.

Allow the pork loin to rest on the rack for 10-15 minutes. While it rests, it should reach an internal temperature of 145°F. Transfer the pork loin to a cutting board. Carve and serve immediately with the sauerkraut.