Boil the water and add to the tea bags in a heatproof container. Let it steep for 10min, and then remove the tea bags. Let this concentrated tea cool.
Add your cooled tea concentrate to a serving pitcher, add the gin and lime juice. Stir. Place ice into the cups and pour over the mixture. As the tea is extra strong, the ice will dilute it so don't skimp! Garnish with mint leaves.