In a saucepan, bring the water to a boil, add the tea, sugar, and mix to dissolve. Set aside to cool for about 20 minutes.
Strain the tea into an airtight container and store in the fridge for up to 10 days.
To serve, mix 1 part of syrup to 1 part of gin, pour over ice, then top with soda water. Garnish with lime wedges and rim the glass with chilli salt, if preferred.
