Jerusalem artichoke soup

Ingredients :
1 onion, sliced
50g/2oz butter
700g/11⁄2lb Jerusalem artichokes, peeled and sliced
600ml/1pt milk
salt and ground white pepper

How to make
- In a heavy saucepan over a low heat, gently sweat the onion in the butter until soft and translucent.

- Add the artichokes to the onion. Cook, covered, for 10 minutes, stirring a few times.
- Add 600ml/1pint water and the milk. Season with salt and pepper to taste, and simmer slowly – do not boil or the milk may curdle.

- Purée the soup using a blender or food processor. Taste and add more seasoning if needed. Reheat gently and serve.