It is either Lomandra bracteata or Lomandra longifolia. Without flower clusters, it is hard to tell the two species apart without a good in focus photograph of an unchewed leaf tip.
Many thanks Betty and Michael I wondered if it was lomandra. This is an exciting find we have located a cluster of them unexpectedly following removal of some thick Chilean needle grass and love grass. I will follow up with photos when they flower. Thanks again :)