Mix the white flour and water into a smooth paste. Put it into the soup. Add some sheet jelly, sesame oil, ginger powder and pepper to the soup. Put some more wood on the fire and keep the soup boiling all the time. Put Mahua (fried dough twist) into the soup when the soup is ladled out. The Mahua is steeped in the boiling soup and becomes soft and curving. It 's the best time to taste it.