Heat the butter in a large pan. Sauté the shallots, add the potatoes and continue to cook. Pour in the stock and add the saffron. Bring the liquid to the boil, reduce the heat, cover and simmer the potatoes over a medium heat for approx. 20 mins. until soft. Puree the soup, season. Plate up the soup, top with the sour single cream, garnish with the saffron threads.
Thread 2 jumbo prawns onto each skewer. Mix the oil with the parsley. Coat the prawns with the parsley oil. Heat the frying pan and fry the prawns for approx. 1 1/2 mins. on each side. Salt the prawns and serve with the potato soup.