Preheat oven to 130 degrees Celsius
Peel feijoas and lay peels on a baking tray lined with baking paper
Dry the peels in the oven, turning them over at 10 minute intervals
Blend the dried peels with caster sugar, sea salt, and citric acid until fine powder
Store the sherbet in an airtight container in the fridge
Use the sherbet to dust desserts, spoon onto ice cream, or add into icing
