That’s funnier than simply using your rice cooker…
Okowa means steamed sticky rice, usually with “gu” (toppings).
There are “classic ones” :
kuri-okowa, with chestnut.
kinoko-okowa with mushroom.
I have twisted the recipes by steaming them inside kabocha pumpkins and using raw chesnuts (instead in syrup ones for most recipe).
The day before : rinse and soak mochigome (Japanese sticky rice). Also soak dry shiitake mushrooms.
Empty a few bochan kabocha (baby sweet pumpkins).
Take out of the shell a few kuri (Japanese chestnuts).
Fill a kabocha with mushroom + rice, another with kuri + rice.
Add liquid. For the mushroom, it’s soy sauce + sake + mushroom soaking liquid. For the kuri, it’s mirin+sake+ a little sea salt.
Keep some mushroom water and rice soaking water for adding while it cooks.
Steam it long enough… add liquid to the rice if needed. That took 3 hours (on low heat on the induction stove).
Cut and eat with goma shio (that means sesame + salt, pounded together. I keep them whole). The kabocha is eaten with its skin.
I found the mushroom version delicious. The kuri was good too. The chesnuts were cooked, but could have been more cooked… Boiling them before might improve that.