Chef JA Cooks

5 Cook Kabocha Squash: Cut the kabocha squash into bite-sized pieces. Steam or boil the pieces for about 10 minutes or until they become tender.
7 Make Kabocha Filling: Let the kabocha pieces cool slightly, and use a knife to remove the skin. In a bowl, mash the kabocha with a fork or potato masher until smooth. Melt the butter and stir it into the mashed kabocha. Add a pinch of salt to taste and mix well to create a smooth filling.
12 Prepare the Pie Sheets: Cut each pie sheet into thirds to create smaller rectangular pieces. For half of the rectangles, make a few small slits on top to allow steam to escape during baking.
9 Assemble the Pies: Place one tablespoon of kabocha filling in the center of an unslit pie sheet. Cover with a slit pie sheet, aligning the edges. Use a fork to press down firmly along the edges, sealing the filling inside. Repeat with the remaining pie sheets and filling.
10 Egg Wash: In a small bowl, beat the egg yolk. Use a pastry brush to lightly coat the tops of the pies with the egg yolk. 
11 Bake the Pies: Line a baking sheet with parchment paper or a silicone baking mat. Place the assembled pies on the baking sheet and bake in the preheated oven at 180°C (350°F) for about 15-18 minutes, or until the pies are golden brown and the crust is flaky.