Prepare the sauce by stirring together all sauce ingredients in a small saucepan and bring to a boil; reduce heat and simmer, covered, for 30 minutes. For the pork, stir together spices in a medium bowl; add pork and toss until coated. Heat 1 tablespoon oil in a Dutch oven or stock pot. Add pork and cook until browned on all sides (in batches if pot is narrow). Remove from pot. Heat remaining oil and add onion; cook and stir over medium-high heat for 5 minutes to brown. Add pork back to pot with mango and 1 1/2 cups mango barbecue sauce (reserve extra sauce for serving); cover and cook over low heat for 2 1/2 hours or until meat shreds easily with a fork. Serve shredded pork on rolls with a drizzle of barbecue sauce. Great with a spoonful of Sweet Mango Slaw on top or served on the side.