Cut the kabocha in half, then cut one in half again to get a quarter. Kabocha is surprisingly hard, so be very careful of your fingers when cutting it.

Remove the seeds from your quarter of kabocha, then wrap it in plastic wrap. Microwave it for 4 minutes to soften the squash and make it easy to remove from the rind. (If you would prefer to make this recipe without using a microwave, see the note at the bottom of the recipe card below).

Be careful handling the hot kabocha. Cut it off of the rind and into roughly equal sized pieces. Set the kabocha pieces aside for now.

Melt butter in a saucepan over medium heat. Add the sliced onion and sauté until it begins to soften.

Stir in the kabocha and sauté it with the onion for another minute.

Pour in the broth. Bring the soup just to a boil, then cover it with a lid and reduce the heat to low. Allow it to simmer for 20 minutes.

Using an immersion blender purée the soup. Or, you can use a blender to purée it in batches.

Pour in the milk. Stir while you wait for the soup to get hot. Don't allow it to come to a boil. Season to taste with kosher salt and freshly ground black pepper.

Optionally, drizzle with a touch of cream and garnish with chopped fresh parsley. Your Japanese kabocha soup is ready to enjoy! I recommend dipping some warm, crusty bread into it.