• 4 wilted cos (romaine) lettuces, cleaned but left whole
• 300 ml (10½ fl oz) rice vinegar
• 200 g (7 oz) honey
• 90 ml (3 fl oz) white soy sauce

Put the lettuces on a hot barbecue or in a frying pan over high heat until the outside leaves are charred and blackened. Mix together the rice vinegar, honey and white soy to make a pickle. Pour the pickle into an airtight container that is large enough to hold the whole lettuce. Add the lettuce to the pickle, seal the container and leave overnight in the fridge. Break off leaves as you’re ready to use them.