1. Wash the rice and moong beans and soak for at least half an hour.
2. Put all the ingredients in a saucepan except for the butter.
3. Bring to the boil, cover and simmer for 40 mins. until cooked to a very mushy appearance. (It may be necessary to add more water during cooking if the mixture becomes too dry).
4. Finally, add the butter and stir in before serving.

Serving suggestion: Serve with a vegetable sak.