In a small bowl, mix together cornstarch and sugar, then set aside. In a saucepan over medium heat, combine chopped canned peaches, diced ripe mango, the cornstarch mixture, a dash of salt, and peach syrup. Stir gently, cooking until the mixture thickens, about 3-5 minutes. Allow the filling to cool to room temperature.

On a clean, flat surface, roll out the puff pastry sheets. Cut the pastry into desired shapes, typically squares or circles. Spoon a generous amount of the cooled peach mango filling onto one half of each pastry shape, ensuring not to overfill. Fold the other half over the filling to create a pocket, then press the edges firmly to seal and crimp with a fork for a decorative touch.

Carefully transfer the assembled Peach Mango Pocket Pies to a baking sheet or plate lined with parchment paper, ensuring they are not touching. Place them in the freezer for at least 6 hours or overnight.

To fry, heat a deep skillet or frying pan over medium heat and add vegetable oil, ensuring it reaches about 350°F (175°C). Fry the frozen pies in batches, cooking for 3-5 minutes until golden brown and crispy. Transfer to a paper towel-lined plate to drain excess oil.

Alternatively, preheat your oven to 360°F (180°C). Remove the pie pockets from the freezer and place them on a baking sheet lined with parchment paper. Lightly brush each pie with an egg wash, poke holes in the tops for steam to escape, and bake for 18-20 minutes until golden brown and puffed up.