Soup for a cold day

Well I am completely and utterly snowed in today, we live at the bottom of a hill and no one is going anywhere. Everything looks absolutely beautiful and it is so quiet. I thought now would be a good time to make a big bowl of soup and luckily I have a full larder as I went shopping before the snow. I am using a recipe from Nigel Slater's kitchen diaries - this is a wonderful book based on the dates and months of the year and by rights this soup should be cooked on January 13th he says!

The one thing he always says to do is keep those parmesan rinds, the nasty ones that have been sitting in the fridge for weeks, they are full of flavour and make this leek and potato soup even more delicious. You will also need -
3 good sized leeks
40g butter
3 medium potatoes
a couple of large hunks of parmesan rind
1.5 litres of light stock or water
a handful of parsley
6 tablespoons of grated parmesan

Trim the leeks, slice them into thick rings, then wash thoroughly. Melt the butter in a heavy based pan and then tip in the washed leeks and let them soften slowly, covered with a lid, over a low to moderate heat. After about twenty minutes and with some occasional stirring, they should be silkily tender.

While they are softening, peel the potatoes and cut them into chunks. Add them to the leeks when they are soft and let them cook for five minutes before dropping in the cheese rinds and pouring in the stock or water. Season with salt and pepper and then partially cover and leave to simmer for forty minutes.

Remove and discard the undissolved cheese rinds, scraping back into the soup any cheesy goo from them as you go. Add the leaves of the parsley and blitz the soup in a blender. Check the seasoning - it does need a surprisingly generous amount of salt and pepper - bring briefly to the boil and serve piping hot with the grated parmesan. This will feed 6.