Wash the plums, cut in half and remove the stones. Place cut-side down in a wide, shallow pan (make sure it’s well-washed; you don’t want any lingering whiffs of onion/garlic to ruin your fro-yo).
Split the vanilla pod along its length, scrape out the seeds and bung the whole lot in with the plums. Add the caster sugar, tea bag and water and heat until you get a few bubbles.
Let the sugary syrup bubble gently for 15-20 minutes to get the flavour from the vanilla pod & tea bag. Turn the plums halfway through to make sure the fruit is completely softened.
Pick out the tea bag and the vanilla pod (I stuck my vanilla in a jam jar of sugar to make some flavoured sugar) and blend the plums along with the syrup until smooth. Let the plum mixture cool down in the fridge for a bit.
When the plum mixture has cooled, mix in the Greek yoghurt and put in an ice cream maker to churn (or pour into a plastic container and freeze, removing the container every couple of hours to beat out any ice crystals).
Because this is a frozen yoghurt, it sets quite firm so take it out of the freezer for 10 minutes or so before you want to scoop.
I like this on its own or with a few crushed Amaretti biscuits sprinkled on top.
