Ingredients

Steps

• Melt butter in a large saucepan over medium heat and cook chopped onion and garlic for 3 minutes until soft.
• Increase heat to high, add watercress and salt, cover, and cook for 30 seconds.
• Add spinach and cook for 2 minutes until wilted.
• Pour in 500ml of boiling water, simmer for 3 minutes, then remove from heat and add ice cubes.
• Blend the soup in batches in a food processor until smooth and transfer to a clean pan.
• Reheat the soup, season with salt and pepper, and serve with a swirl of crème fraîche.