Spanish fish soup with Jerusalem artichokes and puy lentils This is an amazingly feisty and deeply flavourful soup. The combination of  tomatoes, eggs, mackerel and Jerusalem artichokes in this result in a 1+1=50 explosion of "umami" flavouring. Umami is a Japanese word for the 5th unique taste that humans can detect. After salty, sweet, sour and bitter, this 5th taste is a moreish savoury taste that the Japanese have known about since 1908, but those of us in West have only started talking seriously about since the mid 1980's. It may not look like much on first glance, but this soup packs [...]