2.Combine potato, pumpkin, beetroot, parsnip, carrots, lemon, oil, butter and half the oregano in large shallow baking dish. Roast, uncovered, turning occasionally, about 40 minutes or until vegetables are tender.
3.Meanwhile to make dressing, combine juice and mustard in screw-top jar; shake well.
4.Combine vegetables with dressing and rocket in large bowl; sprinkle over cheese and remaining oregano leaves.