Finely slice your onions and leeks and finely diced the garlic and to a large hot saucepan with a little oil. Sauté for around five minutes until everything has softened.
Peel and chop through potato into cubes, peel the carrot and chop into half moons and chop the celery.
Add in the herbs, the chopped vegetables, the chicken breasts, stock cubes, bay leaves, Parmesan rind and the water into the pot. Ensure that the chicken is fully submerged, as the lid and allow to simmer for 45 minutes.
After 45 minutes, removed the rind and bay leaves and discard. Remove the chicken and shred using two forks, return the chicken back into the soup with the chopped fresh kale, mustard and grated Parmesan. Turn off the heat, stir everything together and allow the kale to gently wilt in the residual heat and the Parmesan will melt into the soup.
Serve with an extra grating of Parmesan and a slice of butter sourdough.
