Chop the leek, celery and the carrot.
Heat the oil in a saucepan, then add the leak and celery. Gently sauté them for five minutes, then add the carrot and cook for another five minutes or so.
Pour in the vegetable stock, then add the broccoli and bring to the boil. Simmer for five minutes, then add the shredded spring greens and the drained butter beans. Cook for another five minutes.
Meanwhile make the gremolata: mix the parsley with the garlic and lemon zest into a paste. Add a drop of lemon juice, if it’s too dry.
When the vegetables are tender, turn off the heat and ladle it into bowls. Serve with the gremolata and lemon wedges on the side.