Borlotti Bean Soup with kale and lemon

Peel and chop the onion. Peel and trim the carrots and chop into chunks. Trim and slice the celery stalks.
Heat the oil in a large saucepan and gently fry the onion, carrot and celery for 5 minutes until starting to soften. Peel and crush the garlic and add to the pan.
Drain and rinse the borlotti beans and add to the pan, followed by the vegetable stock and tomato purée. Season well with salt and black pepper. Simmer for 12-14 minutes until the carrots are cooked through.
Spoon about a third of the soup into a blender or food processor and blitz until completely smooth. Return it to the pan and stir through the soup.
Remove any tough stalks from the curly kale and roughly chop. Stir through the soup and simmer for a minute or two until wilted.
Stir through the juice of half a lemon, then taste and adjust the seasoning as required. Serve immediately.