1. Combine canola oil, onion, red pepper, garlic, ginger, and kosher salt in bottom of slow cooker. Mix well.
2. Place pork roast on top of vegetables.
3. In a small bowl, whisk together 1/2 cup of the pineapple juice, rice vinegar, ketchup, soy sauce, brown sugar, Worcestershire sauce, and crushed red pepper flakes. Reserve remaining pineapple juice (about < cup).
4. Pour sauce over meat and vegetables and set cooker for 8 hours on low heat (or 4 hours on high).
5. At end of cooking time, remove meat from sauce with tongs and set aside to cool (about 15 minutes). Strain sauce into a small saucepan (there should be 2 cups). Once meat is cool enough to handle, shred it with your hands or two forks and place it back into slow cooker. Put cooked vegetables on top of shredded meat.
6. Stir together cornstarch and reserved pineapple juice, then whisk into sauce over medium-high heat. Once sauce boils and thickens, about 2 minutes, pour it over meat and vegetables. Stir to combine.
7. Toast large dinner rolls and fill with meat, shredded cabbage, and scallions. Serve hot.
Source: Hannaford fresh Magazine, July - August 2007