Heat the oil in a large saucepan and add the chicken in batches.
Cook the chicken until brown.
Remove chicken and set aside.
Add bacon, carrots, celery and leek.
Fry until brown.
Add a splash of cold water and boil, scraping the bottom of the pan.
Return the chicken to the pan.
Add herbs and cover with cold water.
Simmer until chicken is tender.
Remove the chicken to a plate, cover with foil and leave to cool.
Strain the soup into a clean saucepan and discard all the other ingredients. (I used the veggies to make another soup to save waste)
Leave to stand for a few mins and skim off any fat that rises to the top.
Pull the meat from the chicken bones and tear into large chunks.
Simmer the soup adding the chicken, remaining leeks and prunes for around 20 mins.
Season to taste.
Serve with fresh bread.