Yuzu - a hybrid citrus fruit that is extremely cold-resistant, hence it grows wild in Tibet and central China, but is cultivated in Japan. It isn’t very juicy, so they are crushed whole with salt to extract the juice. They have the flavour of mandarin crossed with lime and grapefruit. They are now being grown experimentally at Seresin vineyard in New Zealand. Fingers crossed it’s successful, as they’re very expensive.