Turn the slow cooker onto sear function. Add the olive oil and bring to a medium heat. Add the bacon and fry until starting to brown before adding the thinly sliced leeks. Sauté until tender.
Once the leeks are tender add the garlic and sauté until fragrant. Add the diced carrot, and celery and sauté for another minute.
Add the dried oregano, dried thyme and tomato paste. Stir and sauté briefly.
Add the remaining vegetables, crushed tomatoes, chicken stock, parmesan rind, beans, and chicken breasts. Turn the slow cooker to slow cook on high for 6 hours.
At around 5 hours and 30 minutes, transfer the chicken breasts to a plate and use two forks to shred the chicken. Return the shredded chicken to the slow cooker along with the pasta. Stir through and place the lid on. Cook for a further 20 minutes or until the pasta is al dente.
Season with sea salt and cracked black pepper to taste.
Remove the bay leaves and parmesan rind and serve hot topped with shaved parmesan.