Heat oven to 375°F In a small bowl, mix spices together for Korean Rub. Rinse pork and pat dry. Pat rub all over pork.
In a large, heavy-bottomed pot, heat oil over medium high heat. Add pork and sear on all sides. Remove from pan and transfer to a roasting pan.
For sauce: Add pears, carrots, celery, onions, garlic and ginger to pot. Cook until tender over medium heat, eight to twelve minutes. Once vegetables are tender, add apple juice and increase heat to medium high, stirring constantly and scraping bottom and sides of pan with wooden spoon to deglaze.
Pour sauce over pork in roasting pan. Cover with foil and bake for three hours.