Place potato starch in a small cup and add ¼ cup (60 ml) water; stir with a teaspoon until the starch is dissolved. Pour ½ cup + 1 ½ tablespoons (140 ml) of water with sugar into a saucepan and bring to a simmer. Stir in the starch mixture and bring it to a boil while constantly stirring with a hand whisk or a spoon.
Once boiled, remove the glaze from the heat and let it cool a bit. Stir every 3-5 minutes to prevent a film from forming on the surface of the glaze. With a silicone brush, gently apply the glaze on top of the fruit to keep the made pattern. Refrigerate the pastry for at least 1 hour before serving.
