Heat the clarified butter in a non-stick frying pan. Fry the Jerusalem artichokes, shallots and thyme for approx. 5 mins., stirring occasionally. Season the topping with salt and set aside.
Heat the clarified butter in a pan. Sauté the shallots, Jerusalem artichokes and potatoes. Pour in the stock, bring to the boil, reduce the heat and simmer for approx. 20 mins. until soft. Add the cream, blend the soup, season. Serve the soup with the topping.