In a large saucepan, soften the onions in the butter for 5 minutes and add the potatoes. Coat the veg in the melted butter and add the vegetable stock.
Simmer for 25 minutes until the potatoes are cooked.
Wearing gloves, wash nettle leaves in cold water. They will still sting when they are wet! The darker the leaf, the more peppery the flavour.
Add the nettles to the stock & veg and simmer for a further five minutes.
Remove the soup from then pan and blend, using a hand blender or a liquidiser.
When the soup is smooth and creamy, transfer to the bowls.
Serve with a swirl of single cream and a few snipped chives to garnish.