Potato and pea soup

1) Heat the oil in a large saucepan and then fry the onion for 5 mins until softened.
2) Add the potatoes and stock. Bring to the boil and then turn down to a simmer and cook for 10–15 minutes, covered, until the potatoes are cooked.
3) Add the peas and cook for a couple of minutes more to heat through.
5) Blend the soup using a hand blender until smooth,
6) Season to taste. Serve topped with the chopped mint.