In a medium saucepan, combine the orange juice, rice vinegar, and sugar over medium-high heat.
Stir continuously until the sugar dissolves and the mixture begins to boil.
Reduce the heat to maintain a steady, low boil.
Add the garlic chili paste and grated ginger, stirring well to combine.
Whisk the potato starch and water mixture (slurry) into the saucepan.
Continue to boil for 5 minutes, stirring occasionally, until the sauce thickens and is no longer cloudy.
Remove the pan from the heat and stir in the salt. The sauce will continue to thicken as it cools.
Serve warm or at room temperature. Store any leftovers in an airtight container in the refrigerator for up to two weeks.
