Preheat the oven to 160ºC. In a large casserole dish, make layers of the lamb, potatoes, onion and carrots, sprinkling each layer with parsley, thyme, chives and pepper. Finish with a layer of potatoes, then pour over the stock.
Cover the casserole with a tight-fitting lid and place in the oven to cook for about 2 hours or until both the meat and vegetables feel tender when tested with a skewer.
Increase the oven temperature to 200ºC. Remove the casserole lid and cook for a further 20 minutes or until the potatoes on top are golden-brown and crisp. Serve hot, sprinkled with more thyme and parsley.