Preheat the oven to 160°C. Using a circular template cut out of baking paper, grate parmesan in rounds onto a baking tray lined with non-stick baking paper. Bake for 5-6 minutes until melted and beginning to crisp. Remove and leave on the sheet to cool, then lift off gently with a spatula. Store in an airtight container between sheets of baking paper to keep them separate. Use the day they are made.