Rinse leeks, Peel carrots, turnips, celery root and onion. Lard onion with the clove.
Rinse the chicken, put in a large pot and cover with cold water and bring to a boil. Add 1 leek, 2 carrots, onion, bouquet garni and peppercorns to the pot and simmer for 30 minutes.
Remove the chicken. Pour the soup through a fine sieve and transfer to a clean pot. Add the chicken back to the pot and simmer for another 30 minutes.
Trim the dark green leaves from the remaining leeks and tie together with kitchen string. Chop the remaining vegetables. Add the vegetables to the pot and simmer for another 30 minutes.
Remove the chicken. Remove the skin and take the meat from the bones. Cut the meat into bite-sized pieces.
Remove the leeks cut into rings. Return the leeks and chicken meat to the pot. Season with salt and pepper and serve.