Jerusalem artichoke soup with crispy onions

1 Heat a large saucepan or casserole dish over a medium heat. Add the oil and butter and, once foaming, add the celery with a pinch of salt and cook for 5 minutes. Next add the artichokes and potato; cook for another 5 minutes until light golden. Add the stock, season and mix well. Cover and cook for 30 minutes over a low heat, until the artichokes and potato are both soft.

2 For the crispy fried onions, heat another pan and add the oil. Once hot, add the onions and cook for 10 minutes over a high heat until golden and crisp; set aside. Once the soup is cooked, blend until smooth, then return to the pan. Bring to the boil, then divide between serving bowls. Top with the crispy onions and serve immediately.