Rocket and Potato Soup

I first came across this simple Italian peasant soup six years ago, when I was writing In Praise of the Potato; it has become a great favourite. Filling, and thick with bread and diced potatoes, ids the peppery, bitter tang of the rocket that transforms this soup into something special. When ids made with water ids good, but I like to add half a stock-cube to give it a bit more body.