Step 1

Boil the water in a large saucepan. Chuck in the tea mix and the sugar. Bash up one of the lemongrass sticks to release the flavour and chuck it into the tea. Boil the tea for 3 minutes before taking it off the heat.

Step 2

Allow the tea to cool and steep for 45 minutes. Strain the tea into a cocktail shaker and discard the leaves and the lemongrass. Add a little ice to the shaker, along with the coconut rum. Shake the tea with the rum.

Step 3

Fill glasses with ice and pour the tea three quarters of the way up. Stir the condensed milk into the double cream. Pour the milk into the glasses and stir with the remaining lemongrass stalks. Serve ice cold.