The technique of smoking as a means of preserving meat and fish has been in use for thousands of years. Commercially smoked fish may be salted first or immersed in brine, then exposed to smoke from hardwoods such as oak, beech or hickory, which not only preserves, but adds flavour. At home you can smoke your own fish using a kettle barbecue or a barbecue with a lid. Special woodchips (sold in barbecue and outdoor stores) give off a wonderfully scented smoke and infuse food with their aroma. Don’t use wood that isn’t specifically intended for smoking food.