In summer, a light pea soup feels totally right – the watercress in this recipe adds a mustardy bite.
Heat a large saucepan and pour in a little olive oil. Throw in the chopped onion and celery. Turn the heat down and cook very gently with the lid on for 10 minutes, or until the onion has softened, but not browned.
Add the potato and stock and bring to the boil. Simmer for 10 minutes or until the potato is cooked. Next, drop in the peas and watercress and simmer for a further 5 minutes until the peas are cooked.
Remove the pan from the heat. Whiz the soup with a hand blender, or in a liquidizer, until smooth. Taste, then season with salt and pepper.
Serve the soup with a spoonful of soured cream swirled in, a drizzle of extra virgin olive oil and some crusty bread and butter.
Tip: You can use frozen peas – just simmer them in the stock a couple of minutes