1) The basic batter becomes too thick. Divide it into three parts as it is. For each layer, we are adding water separately as mentioned in the listed ingredient.
2) For green and white layer just steam it for 10 mins. Within this time the batter will be cooked enough so that it will not mix with the upper layer. For the third layer after 10 min check with a toothpick. It should come out clean. If not than steam it for another 5 mins.
3) For the green color use palak/spinach puree, green coriander puree or mint puree.
4) For saffron layer use carrot puree.
5) It seems that lower layer is steamed for a longer duration. But believe me, it is as moist as the upper layers. There is no sign of hardness.