- Preheat oven to 165°C (330°F). 
- Grate potatoes and set aside. 
- Combine Grace Coconut Milk and water; add to the grated potato and mix well.  Add remaining ingredients and mix well except for the margarine, rum and lime juice. 
- Scrape mixture into a well greased pan and dot with Grace Hello Soft Margarine and bake for about 2 hours. 
- Remove cake from oven and allow to cool. 
- Combine lime juice and rum and pour over pudding before serving.