If you don't own a drop lid, create one using aluminum foil! Take a piece of foil larger that you pot and fold in the edges until it just fits within the pot. Punch holes through the center of the foil with a chopstick so that you have a large steam vent. This will be your drop lid.
Cut the kabocha squash into ~1" cubes. If the kabocha squash is too hard, pop it in the microwave for 2 min to soften and try cutting again.
1/2 kabocha squash
Line the bottom of a pot with the kabocha squash in a single layer.
1/2 kabocha squash
Mix the simmering sauce ingredients together with the dashi stock. Pour into the pot.
1 tbsp soy sauce, 1 tbsp sugar, 1 tbsp minced ginger, 2 tbsp sake, 2 cups dashi stock
Bring pot to boil on high.
Once boiling, turn down to medium low heat to simmer. Cover ingredients with the drop lid and cook for 20-30 min, or until liquid has mostly evaporated and the kabocha squash is tender.
Turn off heat and let kabocha sit in the pot with the pot lid covering to cool, about 30 minutes.
Serve at room temp or chilled.