Divide the chillies, ginger, mint and sugar between 4 tall glasses and muddle with a cocktail muddler.
Set aside 4 litchis for garnish then puree the remaining litchis in a blender – add some of the liquid from the litchis to blend to a smooth puree.
Place 3 tablespoons of the litchi puree into each glass then top up the glasses with the sparkling water.
Serve with a lemongrass in the glass to use as a stirrer.
Helpful Hint: Muddling is a technique used to grind herbs or ingredients in the bottom of the glass using a muddling tool. If you do not have a muddler, use the back of a wooden spoon to gently crush the ingredients to get the desired effect.