1.Heat half the oil in large saucepan, cook lamb, in batches, until browned. Remove from pan.
2.Heat remaining oil in same pan, cook onion, carrot, celery and garlic, stirring, until vegetables soften. Return lamb to pan with stock, the water, barley and thyme, bring to the boil. Reduce heat, simmer, covered, 1 hour, skimming fat from surface occasionally.
3.Add potato, simmer, uncovered, about 30 minutes or until potato is tender. Add cabbage, simmer, uncovered, until cabbage is just tender. Discard thyme.