Bring a saucepan of water to the boil - enough water to be able to submerge all the nettles

Put a large colander into the kitchen sink

Blanch the nettles for about 30 seconds, using a wooden spoon to push the leaves down into the water

Carefully pour the nettles into the colander in the sink and allow all the water to drain away. Allow to cool fully

Finely slice the garlic and grate the Parmesan

Put all the ingredients into a food processor and pulse for about a minute

Decant into sterilised glass jars