Roughly chop the beetroot. Wrap your coconut in a tea towel. Set on a firm surface. Whack with a rolling pin or hammer to crack it open. Catch any juices. Use the tip of a butter knife to prise the flesh away from the shell. Roughly chop. Feed the beetroot and coconut through your juicer, along with the seeds from your cardamom pods. Shake the juice with any coconut juices you saved and 250 ml water, more or less to taste.
Pulp fact: the pulp from this juice makes an awesome, fresh and funky topping for iced cupcakes.