A delicious seasonal recipe, watercress soup is a real treat! Ingredients for 4 people: 2 bunch of watercress (approx 400g) 2 potatoes 1 shallot 1 knob of butter A liter of water 1 tbsp of crème fraîche (optional) Salt and freshly ground pepper Also read: all our articles and recipes dedicated to watercress Watercress soup recipe Start by peeling the potatoes and then washing them under cold water.