Prepare and cook dried peas according to on-pack instructions. Drain and set aside.
Heat olive oil in a large saucepan over medium-low heat. Add leek, celery, zucchini and cook, stirring often, for 5 minutes.
Increase heat. Add potatoes, stock, salt and water to the pan. Cover and bring to the boil. Reduce heat to medium and simmer, partially covered, for 15 minutes or until potato is tender. Add prepared and cooked peas and cook for 3 minutes until heated through.
Serve sprinkled with fresh mint.