Juice the pineapple and mint in a cold-press juicer or blender (strain if blending and discard solids), add kombucha and pour mixture into 100ml moulds, half-freeze (1-2 hours), then insert ice-pop sticks. Freeze completely (2-3 hours). To serve, dip moulds briefly in hot water to unmould. You can also pour mixture over a shallow tray to make granita; allow to semi-set in the freezer then scrape with a fork every 30 minutes to form ice crystals.
Note Kombucha is a fermented tea usually served