Thinly slice the leeks.
Peel and dice the potatoes. Rinse and drain the beans.
Heat the oil in a saucepan, then sauté the leeks and garlic for 5 minutes until softened. Add the potatoes and beans, then pour in the stock.
Bring to the boil, turn down the heat and, under a lid, gently simmer for 20 minutes .
Take it off the heat, add the parsley, then process it in a liquidizer or with a hand-held blender until you get your preferred consistency (creamy or lumpy).
Before serving, sprinkle with some spicy or herby olive oil if you like .