This is my take on a soup with a long history.
Way back in the mists of time, when politicians were honest and I was young, Heinz made Kidney Soup, of which I was inordinately fond. And then they didn’t. I don’t know why – perhaps people were getting squeamish, as many still are, about offal, which is a pity as some of the squishier parts of an animal are among the tastiest, as haggis fans know full well.
So, having a pack of ox kidney in the freezer, and not having a use for it (I’d planned to make a steak and kidney casserole, but forgot to buy the steak), I decided, yesterday, that it’s time for home-made kidney soup.
This is a soup that probably goes back centuries, as ox kidney needs long cooking (though not as long as some recipes suggest), making it unsuitable for frying. (I think some soups have the timing for steak and kidney pudding – I’ve seen 4 hours in some cases.)
I’ve several recipes for it, including one from Mrs. Beeton, which is too much faffing about, as well as being 50-50 shin beef and ox kidney, and takes 3 hours, and another by a Katharine Mellish, from 1901and closer to modern-day standards (cook until tender) but suggests including black peppercorns – not something you really want to bite – or choke – on.
In the end, as ever, I went with what I actually had, which was:-
500g ox kidney
3 Sweet Spear carrots (my favourites, seasonal, from Sainsbury’s)
1 medium parsnip
1 medium onion
2 biggish torpedo-shaped shallots
2 sprigs of thyme, bruised (just rub between your hands)
The leaves from ½ a sprig of rosemary, likewise
¼ teaspoon of celery salt – add more if it needs more salt when finished
1 beef Oxo cube
1 Kallo Organic Vegetable Stock cube
All the old recipes call for “brown stock” – fine if you have a stockpot on the go. Experience has shown that this combination gives an appropriate flavour for meat without it tasting of Oxo.
Ground black pepper to taste.
And that’s all you need – there is ample flavour in the kidneys and aromatics.
First wash the kidney in a colander under cold, running, water, then put it over a bowl to drain (you don’t want blood all over the kitchen).
Cut up the kidney, removing any obvious veins or remaining core – easy to see, they’re white – it’s a bit of a masterclass in micro surgery, so if your knife skills are iffy, try scissors. Don’t worry if you miss some, it’s going in the blender at the end anyway.
Be aware, if you’re at all squeamish, that you might find the texture of the kidney off-putting, it’s soft and squishy, like something that’s been dead a long time; it’s also quite bloody, naturally enough. If either worries you, try wearing disposable vinyl gloves. Closing your eyes while wielding a sharp nice isn’t normally recommended.
Do use a plastic chopping board though – my wooden one is used for nothing messier than bread and/or cheese.
Cut the kidney into smallish chunks, and set aside.
Top, tail and peel the veggies, and cut up quite small.
In a 20cm pan, melt a knob of butter and a splash of olive oil (or if, like me, you’re the sort of person that renders their own fat** at every opportunity, use that, lard, dripping, whatever), a decent teaspoon – I used DIY lard.
**Well, not their own obviously – that’d be icky. Sting a bit, too . . .
When the fat’s melted, toss in the chopped veggies, and sweat over a medium-low heat until the onions are soft but not browned.
While that’s going on, put the kidney in a suitably-sized plastic bag, add about 3 tablespoons of plain flour (I use bread flour), scrunch the top of the bag and toss the kidney around until well coated. Tip into a colander and shake off any excess. Tip: don’t do this too soon, or it’ll bind together into a solid, claggy, mass! Not the end of the world, but a pain in the neck.
In another pan – next size down (18cm, or the same size if that’s what you have), melt a scant teaspoon of fat or add a splash of olive oil. When hot, add about a third of the kidney, and stir around to separate the pieces. Cook until lightly browned but still bloody – this is important – you don’t want bits of leather, remove to a bowl (did I mention there’ll be lots of washing up?), and set aside, do the same with the rest in two portions, adding more fat with each. When the last batch is nearly done, put back the batches you’ve already fried, including the blood which has been given off, hence the bowl. Stir for a minute or two, until the blood stops sputtering (don’t overcook), and add to the veggies. Pour some boiling water into the pan you fried the kidneys in (you could use a frying pan, but a saucepan keeps the mess to a minimum), scraping up anything clinging to the pan. Add the stock cubes and, when dissolved, add to the pan. Top it up with water, until the contents are covered by about half an inch.
Season with celery salt and black pepper, add the herbs, stir well, cover and bring to the boil.** Remove to a smaller ring, reduce to a simmer, stir again and leave for 2.5 – 3 hours, stirring regularly (it tends to stick, for some reason).
**The sources I’ve read exhort you to skim the pan when it’s boiled, but I didn’t get anything to skim, so I left well alone.
Once the kidney is tender – check after 2 hours, it’ll depend on how small you cut it – remove from the heat, discard the thyme twigs, the leaves will have come off, and leave for an hour or so, to cool, longer if your blender has a plastic goblet.
While it’s cooling, wash and dry the 8-inch pan – that’s where your soup will finish.
Blitz the soup in the blender in three batches, pouring it into the smaller pan as you go – it’ll be very thick at this point, so have a kettle of hot water ready. After the last batch has been blitzed, and added to the pan, taste it – it should be rich and taste intensely of kidney.
Pour a little hot water into the blender goblet and, with a spatula, scrape down the sides. Give it a quick whizz at low speed, just to bring water and soup together, and pour it into the rest. Add hot water until you have the taste you want, then season with salt and black pepper is necessary. It will still probably be pretty thick – not a bad thin – and the pan will be almost full. The soup – did you ever doubt it? – is absolutely fantastic. Well, it is if you love kidney soup!
Allow to cool and refrigerate until the following day. All soups, as well as stews and casseroles, benefit from time to allow the flavours to get to know and snuggle up to each other.
By the way, it’s possible, depending on your tastes, that you might get more soup out of this than me by thinning it more. Take care, though – you can easily add more water – you can’t take it out. No reason why, either, you can’t go with tradition and hold back the last third from the blender, to add texture. You’ll have less soup than the smooth version though. Your call…
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