Ensure that the oven is on and preheated to 190C.
Peel and very thinly slice 450g of potatoes.
Quickly par-boil the Potatoes in a pan of boiling water for 2 minutes and then drain.
Grease a casserole dish with a little marg or butter. Try doing this with a piece of kitchen or greaseproof paper.
Wash and thinly slice 200g of leeks.
Layer the potatoes and leeks in the dish (starting and finishing with Potato)
Pour over 275ml of milk (minimum of semi – skimmed but better with full fat)
Dot the top with butter and a sprinkle of nutmeg if you have some.
Put the lid on the dish and Bake for an hour and then take the lid off an bake for a further 30 minutes or until the majority of the milk has been absorbed.