Preheat an oven to 180°C/gas mark 4. Place the nuts into a food processor and blitz to a fine crumb. Add the sugar, butter and flour and blitz until fully incorporated

Add the egg white and vanilla extract and blitz once more – you should be left with a loose batter

Dollop a teaspoon of batter onto a large baking sheet lined with greaseproof paper. Use the back of the spoon to spread it out into a very thin, neat circle. Repeat with the rest of the batter, ensuring there is space between each one (you may need to work in batches or use multiple trays)

Cook in the oven for 7–10 minutes until golden around the edges. If you want the biscuits to be slightly curved, carefully peel them off the tray whilst still hot and drape over a rolling pin or glass bottle