Put the onions in a large pan with the potato, garlic and cold water. Crumble in the vegetable stock cubes and season generously with freshly ground salt and black pepper.
Bring to the boil, then cover, reduce the heat and simmer for 15 minutes or until the potato is very soft.
Remove the lid and add the peas. Bring back to the boil then cover and simmer for another 5 minutes.
Stir in the mint then remove from the heat and leave to cool slightly. Use a stick blender to whizz until it is as smooth as you like, then stir through the cream and season to taste.
To serve hot, return the pan to the heat and warm gently (without boiling) to prevent the cream from curdling. Serve the soup in bowls garnished with a drizzle of cream and a sprig of mint.
6 servings
250ml
* The % Daily Value (DV) tells you how much a nutrient in a serving of food contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.