FAVOURITE THINGS No. 5: JERUSALEM ARTICHOKES

No relation to the more sophisticated Globe Artichoke, these knobbly roots make a delicious, nutty winter soup and are great with potatoes in a gratin, or even as a pizza topping.

My father used to grow Jerusalem Artichokes, and when I was little, I liked to help him dig them up. We'd shake the dirt off them, place them in a colander and take them in for my mum to turn into something delicious. They are neither from Jerusalem nor are they artichokes, but they are easy to grow and push out all sort of lush green growth up top while the gnarly roots develop underground. Their flavour is nutty, strangely redolent of oysters and the merest hint of soil. When pureed, their texture is an unparalleled silkiness. Peel them if the skin is really tough; if not - and these days they come helpfully pre-washed - keep their skins on for added flavour and roughage.

Treat them as you would potatoes: boil them or roast them, slice them and put them in a gratin with lemon, and cook until their skins are crisp and their innards are soft and sweet. But my favourite use for them is in soup. Chop a small onion and fry it until soft. Add a punnet of chopped artichokes, season and cover with water, with a little vegetable stock. Cook until the artichokes are soft and then puree. Add a spoonful of creme fraiche or double cream for added creaminess - not really necessary but it lends a certain sophistication! Sometimes I add parsnips, which makes the soup sweeter. The only down side are the well-documented unsociable after-effects...... I'm not sure I would eat this soup and then teach piano afterwards!