Slice 1/3 of the potatoes, and cut the rest into large chunks
Starting with ½ of the potato chunks, arrange layers in the casserole dish. Chunky potatoes first, then add ½ the herbs, and half the meat. Another layer of potato chunks, the remainder of the herbs, and the remainder of the meat, finishing with the sliced potatoes on top.
Pour 450mls of water over the contents of the casserole dish. Place a layer of foil over the top, before adding the lid.
Cook in the oven at 120ºC for about 2 hours, checking liquid level occasionally and adding extra water if needed (there should be enough liquid left to make a gravy).