- To prepare the katsuo dashi, bring 2 cups water to boil. Add katsuobushi, stir through, and then turn off the heat. Set aside for 15 minutes. Strain the katsuo dashi and discard the katsuobashi. Set the katsuo dashi aside.
- Cut the kabocha into half, remove the seeds and pith using a spoon. Then place it in a bowl and briefly cook it in the microwave on high for 2 minutes. Cut the kabocha into equal wedges lengthwise, and then cut them into 5cm pieces, leaving the skin on.
- Place the equally sized kabocha pieces in a large wide pot, skin side down. Make sure that the pot will fit all of the kabocha pieces in one single layer.
- In a bowl, add in the prepared dashi, sake and sugar. Mix well until sugar is dissolved, then pour into the large pot with kabocha pieces. Bring it to a boil and continue to cook on medium high heat. Add soy sauce and salt, and swirl the pot to mix the liquid well. Make sure that the liquid covers most of the kabocha, you may add a little more water if neccesary. Once the liquid is boiling, turn down to medium low heat to and allow to simmer. Cover with lid and cook for 15-20 minutes or until kabocha is cooked and tender.
- Remove from the heat and let it cool for about 30 minutes. This dish may be served at room temperature.