Watercress Soup with Lemon Crème Fraîche

Heat the olive oil in a large pot or saucepan over medium heat.

Add the chopped onion and cook until softened, about 5 minutes.

Add the diced potato and cook for another 5 minutes, stirring occasionally.

Pour in the vegetable broth, bring to a boil, then reduce heat and simmer for 15 minutes, or until the potato is tender.

Stir in the watercress and cook for 2-3 minutes, until wilted.

Remove the pot from the heat and carefully blend the soup using an immersion blender until smooth. Alternatively, transfer the soup in batches to a regular blender and blend until smooth. Be careful when blending hot liquids.

Season with salt and pepper to taste.

In a small bowl, combine the crème fraîche, lemon zest, and lemon juice.

Ladle the soup into bowls and top each serving with a dollop of lemon crème fraîche. Serve immediately.