Jerusalem Artichoke and Potato Soup with Mustard Croutons

Peel the artichokes and potatoes and cut into small chunks. Place in a bowl of cold water with the lemon juice. This stops the artichokes from turning brown. Heat the olive oil and butter in a large saucepan and add the onion, celery and garlic with a good pinch of salt. Cover and cook for 10 minutes until the vegetables are soft. Drain the artichokes and potatoes and add to the pan. Cook for 5 minutes. Add the stock, season and bring to the boil. Simmer for 30 minutes or until the vegetables are tender. Cool a little then process in batches in a blender or food processor until smooth. Tip into a saucepan and stir in the cream. Reheat gently if needed.

Croutons: Preheat the oven to 180˚C. Place the bread in a large bowl. Combine the remaining ingredients and pour over the bread, turning well to coat in the butter mixture. Tip onto a lined baking tray and bake for 10 minutes, turning occasionally, until golden and crisp. The croutons can be made 1 day ahead, cooled and stored in an airtight container.

To serve: Ladle the soup into warm bowls and top with the mustard croutons and chives. Drizzle with a little extra cream if desired. Makes about 8 cups.