Place pork, rind-side up, on a plate. Pat dry with paper towel. Place in fridge, uncovered, overnight to dry out the rind.
Preheat oven to 240°C. Use a small sharp knife to score the rind at 5mm intervals. Brush with olive oil and rub with sea salt. Place pork in a roasting pan. Cook for 30 mins or until the rind is crackling and golden. Reduce oven to 180°C. Roast the pork for a further 45 mins or until pork is tender.
Meanwhile, to make charred salsa, place a chargrill over medium heat. Add pineapple, corn, cucumber and chillies. Cook, turning often, for 10 mins or until lightly charred. Set aside to cool slightly. Cut the corn kernels from the cob. Remove and discard the chilli skins. Chop the chillies, cucumber and pineapple into 1cm pieces. Place in a large bowl with corn, mint and coriander. Add the vinegar and lime juice. Season. Gently toss to combine.
Cut the pork belly into 2cm-thick slices. Transfer to a serving platter and top with salsa. Serve immediately.
