• Scoop out the seeds from the kabocha.
• Cut the kabocha into smaller pieces. Steam until softened (about 15 minutes).
• Remove the skin of the kabocha. Place kabocha pieces into a medium sized bowl.
• Finely chop the onion. In a medium pan, heat oil on medium. Cook the onions until translucent.
• Add the onion to the kabocha and mix, while making sure to break up the kabocha well.

Now make the bechamel sauce:

• In a small saucepan, heat the butter on medium-low heat.
• Once melted, whisk in 2 tbsp flour until it bubbles (make sure not to burn it).
• Take your hot milk and pour it in and continue to whisk.
• Add salt and pepper to taste and whisk until the sauce thickens.

Now back to the pot pie:

• Add the bechamel sauce to the kabocha mixture in the bowl. Mix well - until creamy.
• Add salt & pepper to taste.
• Transfer the mixture into a casserole dish.
• Open up the canned herring and place on top of the kabocha mixture.
• Place shredded white cheese or grate white cheese on top of the herring.
• Prep a sheet of puff pastry dough. This can be pre-made or you can make it from scratch.
• Place a thin sheet of puff pastry dough over to cover the casserole. You can cut it to fit the casserole or let it hang over the edges.
• Using another sheet of puff pastry dough, cut out the fish design and place it on top of the casserole.
• Mix your egg wash ingredients. Put egg wash onto the dough, being careful not to create any pools.
• Place cut olives around the edge of the dish.
• Preheat the oven to 375 degrees F. Bake the pot pie for 25-30 minutes.
• Enjoy immediately. いただきます (itadakimasu)!