The following day, drain, rinse mung bean. Place into a pot, add in 4c water. Bring to boil for 7 mins, covered. Turn the heat off, leave it on the stove, still covered, let rest for 30 mins. Do the same with the black glutinous rice, in a different pot.
After 30 mins. Add sugar to each pot. Add bruised ginger to mung bean plus pandan leaf. Bring both pots to boil, covered, on medium-high heat for 15 mins for mung beans (or until desired porridge texture) 20 mins for black glutinous rice (or until desire porridge texture).
In a bowl, pour in coconut milk, stir in salt and add in pandan leaf. Warm in microwave for 2 mins.
To serve, place each porridge into a serving bowl, top with coconut milk.