Wash and chop the leek separating the green from the white parts.
Cook the chicken and the green of the leek along with the peppercorns in 500ml/1 pint of water.
Bring to the boil then lower the temperature and simmer for 30 minutes.
Remove pan from heat and set aside for 1 hour to allow flavours to develop.
Remove the chicken and pour soup through a sieve and discard leek and peppercorns.
Chop the chicken meat and return to the pan along with the soup liquid plus the white of the leek, the prunes and the parsley.
Simmer for 10 minutes.
You can now remove the prunes and discard them as they have released their flavour.
Serve soup with crusty bread or crutons if you wish and season to taste.