Place the caster sugar and water into a small saucepan over a medium heat
Over a medium heat, stir until the sugar is dissolved
Bring to the boil for about 5 minutes until thickened

In a small bowl, mix the garlic, ginger, cayenne pepper, chilli flakes, lime juice and soy sauce into a paste
Add the paste into the sugar syrup and boil for another 1-2 minutes
Remove from the heat and allow to cool