I used 3 types of sweet potatoes to cook this soup, the orange, yellow and purple species. The different varities of sweet potatoes gave the soup a very colourful appetising look to it. A very simple soup to cook. Just cut up the sweet potatoes into cubes and boil with enough water and a knotted pandan (screwpine) leaf for fragrance. When the sweet potatoes are tender (about 20 minutes) add sugar and coconut milk to taste. Can opt for just sugar if you are not into coconut milk. Served hot or cold, both versions are just as good. For breakfast, I usually served it hot to warm up our bodies before the start of the day.