Begin by chopping the chili peppers—coarsely if using an immersion blender, or finely if blending is not planned. For a moderate to hot sauce, deseed half of the peppers. To achieve a milder result, remove seeds from all but one or two.

Combine the chopped chilies, vinegar, water, sugar, garlic, ginger, and salt in a saucepan. Bring the mixture to a boil over high heat. Once boiling, lower the heat and allow it to simmer gently for 30 to 45 minutes until the volume is reduced by half.

Using a stick blender, purée the mixture cautiously to your preferred texture. Retain some chunks and seeds for visual appeal and texture, but exercise caution as the hot liquid can cause severe burns. As an alternative, let the mixture cool before blending or omit this step if the chilies were finely chopped.

Place the blended sauce back on the stove and bring to a low simmer. In a separate small bowl, combine 1 tablespoon of potato starch with 2 tablespoons of cold water to create a slurry. Stir this slurry into the simmering sauce and cook, stirring consistently, for several minutes until it thickens. If a thicker consistency is preferred, incorporate an additional teaspoon of starch mixed with 2 teaspoons of cold water and continue cooking.

Remove the sauce from heat and allow it to cool completely before transferring it into sterilized bottles or jars.