This is one of the first things I ever made - and remains a real favourite - sometimes nothing else will do!
The recipe is based an old one of Delia's - I use veg stock instead of chicken - and don't add chives at the end - but pretty much everything else remains the same.
4 large leeks
1 onion chopped
50g butter
1 ltr veg stock
275ml milk
salt and pepper (generous)
To serve
2 tbls cream
1 Trim the leeks, cut in half lengthways, and slice finely.
2 Rinse in a colander and set aside
3 In a large sauacepan, melt the butter, and add the leeks, potato and onion. Stir well so that they all get coated in the butter.
4 Season well with salt and pepper, then cover and let the vegetables sweat over a low heat for about 15 minutes.
5 Add the stock and milk, bring to a simmer, and then cover on a gentle simmer for 20 minutes, until the vegetables are getting soft.
6 Blend with a hand blender / liquidiser
7 Serve with a swirl of cream
I always have this soup hot - though it can be served cold as Vichyssoise (though not quite so good in the snow........)