Leek and potato soup is a classic british recipe, it is a winter favourite when served warm. But cold, the soup is perfect for a summer lunch or even on a picnicleek and potato soup is also known as vichyssoise and is believed to have originated in france though there are many other claims on the origin of this classic soup. Wherever it comes from, a leek and potato soup is both delicious, easy and cheap to make. What is not to like?