Sterilize enough jars to hold 2 cups (I used 2x1cup) by either putting them through the dishwasher on a hot setting or popping them in the oven. Turning it on to 100C (212F) and letting it stay at temp for a good 15 minutes. Then turning off the oven and allowing to cool back to a temperature thats OK to touch (don’t fill super hot jars – they’ll crack). Meanwhile, soak cashews in plenty of water for at least 15 minutes.
Drain cashews and add to a food processor with the boiling water. Process until as smooth as you can get it (at least 5 minutes). Scrape down the sides as you go.
Add the yoghurt starter culture and pulse to combine.
Fill your cooled jars with the cashew mixture. Seal with a lid and keep somewhere warm for 2-4 days or until the yoghurt tastes tangy.
Keep in the refrigerator. If you get some white mould growing just scoop it off. But other coloured moulds should be discarded.