Combine first 8 ingredients in a large zip-lock bag. Add pork to bag and marinate in refrigerator at least 2 hours or overnight.
Place pork and marinade in slow cooker and cook on low for about 8 hours.
Remove pork and place on cutting board. Add cornstarch to broth and stir to combine. Add to marinade in a large pot and boil one minute to thicken. Shred pork and add to sauce. 8 servings.