Step 1

Combine 1/2 cup water, the rice vinegar, sugar, garlic and chile flakes in a small sauce pan. Heat over medium heat, stirring to dissolve the sugar.

Step 2

Bring to a simmer and simmer for 5 minutes, stirring occasionally.

Step 3

In a cup or small bowl, make a slurry of the cornstarch and 1/8 cup water.

Step 4

After simmering the sauce for 5 minutes, slowly pour in the cornstarch slurry. Bring the sauce to a boil and boil gently for 1 minute, stirring constantly. If the sauce isn't as thick as you want, boil for another minute.