1.Place porcini mushrooms in a small heatproof bowl with the water, stand 15 minutes or until softened. Drain, reserve porcini and the soaking liquid.
2.Meanwhile, discard as much skin as possible from chicken. Place chicken, onion, garlic, stock, barley, rosemary, thyme, parsnip, kumara, celery, swiss brown mushrooms, porcini mushrooms and reserved soaking liquid into a 4.5-litre (18-cup) slow cooker. Cook, covered, on low, 6 hours.
3.Remove chicken from cooker. When cool enough to handle, remove meat from bone, shred coarsely. Discard bones. Return meat to cooker, season to taste. Serve topped with parsley.