Place sugar into a clean and sterilised large jar (approx 700ml), add in the warm water and stir well to dissolve.
Add the vinegar and stir until the sugar is fully dissolved.
Add in finely minced garlic and stir to combine.
Add in fish sauce and stir to combine.
Once the fish sauce has been added, taste the sauce and adjust to your liking.
Add in minced chillies a bit at a time and stir well. Taste to check the spice levels, if it's hot enough for you then stop, if not keep adding more. Make sure you are always slowly adding and tasting when it comes to this sauce. It's always easier to add more than to try to fix a sauce that is either too hot, salty or sour. If it tastes too salty or sour add in a dash of water to dilute it.
Close the jar with the lid and place into the fridge. This will keep for up to 4 months.
Pour it over anything and everything you like!
