Ingredients
1 tbsp butter
¼ onion, diced
110g/4oz watercress
150ml/5fl oz vegetable stock
55ml/2fl oz double cream
2 tbsp fresh mint, chopped

Method
1. Melt the butter in a medium saucepan.
2. Add the onion and sauté until soft.
3. Add the watercress.
4. When the watercress has wilted, add the stock.
5. Leave the soup to simmer for 4 minutes.
6. Transfer the soup to a food processor and blitz until smooth.
7. Return the soup to the pan, add the cream and simmer for 2 minutes.
8. Add the mint before removing soup from heat.
9. Ladle the soup into bowls and serve.