What lingers in your fridge? What are the foodstuffs that you either a) always have too much of and/or b) hang on to because it/they will, of course come in handy at some point? I am guilty of always having too much dairy. Too many pots of cream and crème fraîche, too many types of cheese and, as I discovered this weekend, too many Parmesan rinds. Ever since I read (first in Nigel Slater then in Locatelli) that you should never throw away the fag-ends of a lump of Parmesan, the bits of rind that still have a bit of cheese on but are impossible to grate, because they are perfect for enriching soup, I have been diligent about keeping them. Unfortunately, however, I have not been diligent about using them and, when I defrosted my fridge this weekend I found about six.

It was, I decided, time to put the ‘enriching soup’ theory to the test. And where better than in what, at first, seems like a standard leek and potato soup, the sort of soup that is easy and delicious, yet just that little bit pedestrian and therefore crying out for a bit of dressing up. But, oh my, this is so much more than leek and potato soup. In fact I really don’t think it can be called that: leek and Parmesan is a little better but, really, you have to try this to believe how good it is. The three things that make it special are: 1) cooking the leeks very slowly in butter at the beginning; 2) the cheese rinds and 3) the parsley. The first makes the leeks wonderfully tasty, the second make the soup rich without being sickly and the third gives a leek soup something that is usually missing: colour. This is just what you need as ‘real’ winter descends and, what’s more, you can make it in less time than it would take to buy a pot of soup in the supermarket and, of course, it tastes ten times better. Honestly, it’s a revelation.

Leek, potato and Parmesan soup (adapted from The Kitchen Diaries)

For two portions you will need:

Cupboard (or things you may already have)
butter, good lump (about 20g)
potato, 1 medium
chicken stock, 500ml (or a cube)
some Parmesan rinds (I used three of my stash)
sea salt and black pepper

Shopping list
leek, 1
Parmesan, about 25g lump (or 2 tablespoons, grated but, obviously stuff you’ve grated yourself…)
flat-leaf parsley, a small handful (about 25g)

How to
1. Top and tail the leek, removing the harder outer leaves if necessary. Cut it in half lengthways and rinse well under cold water. Slice thinly.
2. Put the butter into a lidded casserole over a medium heat and, once melted, add the leek slices. Once coated in butter cover the pan and leave over a low heat to soften and melt for about 20 minutes, lifting the lid to stir them from time to time and check that they are not burning or browning.
3. Meanwhile, peel the potato and chop into small cubes, make up the stock if necessary, grate the Parmesan and rinse and chop the parsley.
4. Once the leeks are soft, add the potato cubes, stir into the buttery leeks and leave to cook for about five minutes.
5. Add the cheese rinds and stock to the pan, half-cover it and leave it to cook for another ten or fifteen minutes or so.
6. Once the potatoes are soft, remove the rinds. They will have melted into a gooey mess in the soup so make sure you scrape as much melted cheese as you can back into the soup before chucking the hard bits.
7. Add the parsley, blend (off the heat) then return the soup to the heat and bring to the boil. Check the seasoning and serve hot with the grated Parmesan on top.