Heat the oil in a large pan, cut each chicken breast into 4, dust in the flour & brown in the hot oil for 4-5 minutes. Add the squash & leeks,& cook for a further 2-3 minutes.
Pour in the hot stock & add the barley.bring to the boil, then cover & simmer for about 45 minutes until the stock has reduced & the barley is tender.
Stir in the cheese, mix until melted, then add the parsley & season.