1.Tie the pork with kitchen string at 2cm intervals. Heat half the oil in a large frying pan over medium-high heat; cook the pork until browned. Transfer to a 4.5-litre (18-cup) slow cooker.
2.Meanwhile, cut capsicums lengthways into eighths; discard seeds and membranes.
3.Heat remaining oil in same pan over medium heat; cook onion, celery and garlic, stirring occasionally, for 5 minutes or until softened.
4.Add sugar; cook, stirring occasionally, about 10 minutes or until golden and caramelised. Add vinegar to the pan; bring to the boil. Stir in paste and stock; bring to the boil, then pour over pork. Add sultanas and capsicum to the cooker.
5.Cook, covered, on low, for 8 hours. Carefully remove pork from cooker; transfer to serving plate, cover to keep warm.
6.Meanwhile, toast nuts in a dry frying pan, stirring continuously over medium heat until just golden. Remove immediately from pan. Spoon sauce over pork. Serve sprinkled with nuts and parsley.
‘Agrodolce’ is the Italian word used to describe the flavours in this dish and means ‘sour sweet’.Note