Heat oven to 200°C (180°C fan) and rub butter on inside of casserole dish.
Layer ingredients in the casserole, beginning with potatoes, followed by vegetables and then meat, seasoning with salt, pepper and marjoram between the layers. Top with a neat layer of potatoes and season again.
Pour stock over casserole, cover and cook for about 1 1/2 hours until meat is tender.
Brush potatoes with remaining butter 20 minutes before the end of the cooking time and cook uncovered until the potatoes are golden.
TIP: Much of the potato's nutrients lie just under the skin so leave it on.