Add sugar and water to a medium saucepan. No need to stir.
Bring the mixture to a boil and then allow it to simmer until the sugar is completely dissolved, approximately 5 minutes.
Remove from the heat and allow it to cool for a few minutes, then stir in the passion fruit purée while the syrup is still warm. Place it in the refrigerator until chilled, at least 30 minutes.
Follow the instructions on your ice cream maker. After the sorbet sets, I like to place it in the freezer for at least 2 hours to firm up.