Trim fat from lamb. Peel potatoes and slice a few and halve the rest.
Put sliced potatoes in a layer in a heavy saucepan. Cover with meat then the halved potatoes, then remaining ingredients except for chopped parsley. Bring to simmering point, cover tightly and simmer on low heat for approx 2-2 ½ hours until lamb is tender and the stew is thick and creamy. Shake pan gently from time to time to prevent sticking. Remove herbs and serve sprinkled with chopped parsley.