Put the beans, half the parsley and the garlic into a pressure cooker along with enough water to cover them by a couple of centimetres. Cook for 45 minutes until the beans are soft and tender.
Once the beans are done add some butter to a pan and cook the leeks and spring onions gently for about 10 minutes until softened. Add the potatoes, courgettes, salt and wine along with the vegetable stock and cook for 20 minutes.
Once the potatoes are tender add the beans and juice from the pressure cooker as well as the lemon and double cream and serve garnished with the remaining parsley.