1. In a food processor blend the Fresno chilies, Thai chilies, and garlic.
2. Heat together the sugar and water until the sugar is completely dissolved.
3. Add the vinegar and blended chilies.
4. Season with salt and fish sauce and simmer for 5 minutes.
5. Mix together cornstarch and water and pour that into the sauce to thicken.
6. Leave that in the fridge for when you want to use it.
