Bruise the cardamom pods and slice the cucumber. Put them both in a large jug and add the chamomile teabag, mint leaves, lemon zest, cloves and rosemary. Top up with 500ml cold water. Leave to infuse in the fridge for 2-4 hrs. To serve, strain the infused water and pour 50ml of it into each glass. Top up with tonic water and lots of ice. Garnish each one with a few more mint leaves and pomegranate seeds, if you like.