This watercress soup is an absolute delight. The bright color, delicate smell and smooth taste will wake-up your senses.
Sweat the onion, celery and potato in 2 tablespoons of butter over low heat, in a large covered saucepan, for about 10 – 15 minutes until the potato is soft. Cover with water and bring just to a boil, then remove from heat. Cool slightly and ladle the mixture into a blender until half full. Blend to mix. Add a couple of handfuls of watercress and blend until smooth and bright green. Repeat until all the soup is blended and return to soup pot. Season with salt, pepper and a liberal squeeze of lemon.
To garnish, add a swirl of cream or a dollop a of crÃ¨me fraiche. To keep it vegan, use coconut milk.