For this dish you can use the shoulder or other slightly tougher cuts of lamb. This meat is very tasty and juicy, but it requires a bit more time to cook or roast than more tender cuts.
Use a large casserole dish and brown the meat in a small amount of oil.
Cut the onions, celeriac and 3 of the apples into small and large pieces and add to the casserole.
When the vegetables are tender add the lamb stock and a cinnamon stick and bring the casserole to the boil. Allow to simmer for 1 to 1½ hours.
Keep an eye on the casserole and add a bit more water if it starts to boil dry.
Towards the end of the simmering time add salt to taste, along with the celery and the rest of the apples.
Serve in deep plates.