Prep: rinse greens and remove any tough/woody stems. Rinse peas under hot water if frozen. Finely slice the fennel bulb, leek, celery and shallot. Mince garlic, wash peel and chop the potato.
Heat olive oil in a large pot then add shallots, fennel and leek, cook till softened. Add garlic, cook another minute, then add peas, potato and stock. Bring to a boil, reduce to a simmer, and cook (covered) for 10 minutes.
After 10 mins, remove the lid and add greens, cook for a further five minutes then remove from heat and blend till smooth.
Serve with a sprinkle of chia seeds and a sprig of fresh watercress.