Mix together the marinade ingredients and pour over the pork. Cover and leave in the refrigerator to marinate for several hours or preferably overnight, turning the meat occasionally. Remove the pork from the marinade. Heat a small, non-stick frying pan. Add the pork and quickly brown on both sides. Reduce the heat and cook for approximately 6 minutes each side or until thoroughly cooked. Remove from the pan and keep warm. Add the marinade to the pan and bring to the boil, stirring. Simmer for approximately 3 minutes to reduce and thicken slightly. Stir in the peppercorns and mango slices and heat through. Serve the sauce spooned over the meat, accompanied by baby new potatoes and a mixed green salad. NOTES : This recipe uses Waitrose Pork Medallions which contain less than 5% fat. Look out for the Diet Choice symbol on our packs. The pork is pan-fried and finished with peppercorns and slices of fresh mango.