Cut the kabocha into quadrants. Remove the seeds and stringy bits with a knife and/or spoon.
Place the pumpkin into a steamer and steam them over rolling boiling water until the pumpkin is tender and soft.
Cool down the pumpkin until it’s easy to handle. Cut the skin off from the flesh and discard. Chop the pumpkin into smaller chunks.
Place the pumpkin, water (3 cups), sugar and the salt into a blender. Blend it until pureed.
Pour the liquefied pumpkin into a medium size saucepan and boil it over medium high heat for 10 mins. Stir it often to avoid it burning.
The porridge can be served warm or cold. The unused portion can be refrigerated for a few days or frozen for a month. It reheats well in a microwave but make sure you cover with a microwaveable lid to avoid a messy clean up afterwards.