Chef JA Cooks

13 Preparation: Peel the sweet potato, cut them into evenly-sized pieces, and place them in a bowl. Add enough water to cover the sweet potatoes and soak for 5 minutes.
5 Cook Sweet Potato: Steam or boil the pieces for about 5-7 minutes or until they become tender. 
7 Make Sweet Potato Filling: Transfer the cooked sweet potatoes to a bowl and mash them until smooth using a fork or potato masher. Add butter, soy milk, and a pinch of salt, then mix well until combined.
9 Assemble the Pies: Cut the pie sheet in half to create square pieces. Place one tablespoon of sweet potato filling in the center of each square. Fold into triangles and press the edges firmly with a fork to seal. Make a few small slits on top to let steam escape during baking. 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 it and bake in the preheated oven at 180°C (350°F) for about 15-18 minutes, until the pies are golden brown and the crust is flaky.