3 tablespoons butter
1 medium onion, peeled and diced
salt and freshly ground black pepper
6 cups (1.5l) water
450g potatoes, peeled and diced
225g (about 9 cups) of watercress leaves and tender stems
1 cup (150g) fresh or frozen peas
Melt the butter. Add the onion, season with salt and pepper, and cook over medium heat, stirring frequently until the onion is translucent, about 5 to 6 minutes. Add the waterﾠand dicedﾠpotato and cook, partially covered, until the potato cubes are tender, about 10 minutes.
Turn off the heat and add the watercress and peas, stirring a few times to wilt the cress.
Puree the soup using an immersion blender. ﾠIf you want a creamier soup, blend a few tablespoons of heavy cream or creme fraiche into the soup
Once the soup is pureed, rewarm the soup in the pot, season with salt and pepper, and serve.
You can garnish this soup in any number of ways – from a spoonful of yogurt or cream swirled over the top with fresh herbs, to a handful of seeds or bits of crumbled bacon strewn over the top.