When your nettles are ready for blanching, bring a pot of water to a boil ... In fact, there's actually a World Nettle Eating Championship in which people willingly consume as many raw nettle ...

Bring a pot of salted water to the boil and add the nettle leaves. Cook for 10 seconds then cool, drain and pat dry on kitchen paper. Chop the parsley. Cook the onion in the butter until soft.