1. In a small pot, mix the sugar and vinegar together, then gently heat on low until all the sugar is dissolved, stirring every now and then. Leave to cool completely.
2. Add sliced green chillies and sliced garlic into a 1L sterilised jar.
3. Pour in sugar and vinegar solution to fill the jar. Give the jar a jiggle and tap on the bench top to release any trapped air pockets. Screw on the lid and refrigerate.
Ready to devour in a couple of days (once the chillies lose their vibrant green colour)