Add the water, rice vinegar, chili garlic sauce, sugar, cornstarch, minced garlic, red pepper flakes, and salt to a small saucepan.
Bring to a boil over medium heat and simmer for about 1 minute stirring constantly with a whisk until all sugar is dissolved and the sauce becomes thicker and less cloudy.
Turn off the heat and allow it to cool. (It will thicken as it cools.) Place in a small bowl for dipping or store in a glass jar for later.
Notes
Adjust the thickness of the sauce by adding slightly more or slightly less cornstarch.
Be sure to add the cornstarch to the pan before turning on the heat. It will not dissolve correctly in hot liquid.
You can omit the cornstarch and use it as a salad dressing too.