Add the peeled and chopped onion, chopped celery and peeled and finely chopped garlic to a pot on a high heat. Stir regularly for a few minutes until the onions start to soften. If things start to stick to the side of the pot, add a splash of water.
Add the chopped mushrooms and peeled and chopped carrots. Turn the heat down a little and continue to stir regularly for another 2-3 minutes. The mushrooms should start to release some water, but add a splash to the pan if things start to stick.
Prepare the vegetable stock with boiling water, and add to the pot. Add the peeled and chopped potatoes to the pot, along with the drained cannellini beans.
Strip the kale away from any tough stems and chop roughly. Add to the pot (not including the stems)
Add the tomato puree and vinegar to the pot along with the thyme, bay leaves, and rosemary.
Bring the pot to a boil and then turn down to a gentle simmer for around 20 - 25 minutes until the potatoes are fully cooked and you can stick a fork through them without any resistance.
Stir in the chopped parsley reserving a few leaves for garnish if you wish.
Serve in bowls and season with a little salt and pepper if desired.