Step 1

Cut a few thin rounds of lemon and reserve for garnish. Zest 2 tablespoons of zest from the remaining lemons, then juice the lemons (you'll need 4 tablespoons of juice; reserve any additional juice for another use).

Step 2

Make the ice cubes: Stir the lemon zest, 2 tablespoons of the lemon juice, 2 tablespoons of the sugar and the hot water in a heatproof liquid measuring cup. Pour the liquid into a standard ice cube tray and freeze.

Step 3

Make the cocktail: In a mixer, shake together the tea, whiskey, 2 tablespoons lemon juice and remaining 2 tablespoons sugar. Shake and set aside for the sugar to melt.

Step 4

Serve: Arrange a few ice cubes in 2 glasses. Add a couple of ice cubes to the mixer and shake. Pour half of the cocktail mix into each. If you like, run the edge of the glasses with the lemon slices. Garnish the glass with the slices.