4 whole garlic cloves, peeled
4cm/1½in piece ginger, thickly sliced
½ leek, sliced (or 1 small onion, sliced)
2 tbsp oyster or teriyaki sauce
175ml/6fl oz dark soy sauce
75²µ/2½´Ç³ú sugar
3 tbsp mirin
500g/1lb 2oz skin-on piece pork belly, rolled