I cooked this for my hubby as desert yesterday.. emm..yummy. The banana was riped enough and it gave an extra flavor for this desert. This was how I cooked it, I boiled the sweet potatoes with some water, 'gula merah', sago and pandan leave. When the potatoes was almost tender, I added the bananas and coconut milk. Stir and let it simmer for a while and off the heat. Let it cool a bit and served. Enjoy!