Method
Put the scallions into a large pan with the potato, garlic and stock. Bring to the boil, turn down the heat and simmer for 15 minutes or until the potato is very soft.
For the garnish, blanch 3 tbsp of the shelled peas in boiling water for 2-3 minutes, drain, put in a bowl of cold water and set aside. Add the remaining peas to the soup base and simmer for 5 minutes.
Stir in the mint, sweetener and lemon or lime juice, cool slightly then pour into a food processor and whizz until as smooth as you like.
Stir in half the soured cream, taste and season with salt and pepper.
To serve the soup cold, cool quickly, then chill – you may need to add more stock to the soup before serving as it will thicken as it cools. To serve hot, return the soup to the rinsed-out pan and reheat without boiling.
Serve the soup in bowls, garnished with mint, the remaining cream and the drained peas.
If you enjoyed this recipe, try our Spiced Roots Soup.