Heat the olive oil in a large saucepan over medium heat. Add the onion and sauté for about 5 minutes until softened.
Stir in the garlic and cider vinegar, cooking for another minute.
Add the chopped carrots and ginger, then pour in the vegetable stock. Bring to the boil.
Reduce the heat and simmer for 20 minutes, until the carrots are tender.
Add half of the cannellini beans and a handful of parsley leaves to the pan. Blend the soup with a stick blender until silky smooth.
Stir in the remaining beans and season generously with black pepper. Gently reheat.
Serve hot, topped with fresh parsley leaves and a drizzle of cider vinegar if desired.