Another week, another we’re-not-eating-quite-what-we-thought-we-were story. This time, it’s the news that 24 of 60 takeaway meals sampled by Which? contained meat other than the advertised lamb.

Of these, twelve included cheaper meats in addition to lamb; seven contained no lamb whatsoever; and five had been so heavily processed that the scientists were unable to identify what meat(s) they contained. In other words, we can decipher the human genome, but not the doner kebab.

Granted, none of this is very pleasant. It’s undoubtedly fraudulent. Depending on what the mystery meat turns out to be, it could be stomach-turning. (The Mail, with characteristic restraint, took the discovery of the “UNIDENTIFIED” meat as its cue to ask, “Is there rat in your kebab?”)

But is it surprising? Hardly.

As long as there are humans, there will be fraud. And while we tend to think of fraud in purely financial terms, it occurs in relation to any tradeable commodity, from fine art to fishcakes. As such, every government devotes resources to combating it.

But not every form of fraud is pursued with equal vigour, or with equal success. Tax fraud might cost the UK 16 times as much as benefit fraud, but you’d hardly know it from reading the papers or listening to Government ministers. And food fraud, no matter that it has existed for as long as food trading, barely enters our consciousness until a particular scandal happens to capture the attention of the media and the public.

The inevitable consequence of such a scandal is that we get terribly worked up about one particular symptom, with no great attention paid to the others (let alone their causes). Such was the backlash to last year’s revelations, it’s unlikely we’ll find much horse in our burgers for the foreseeable future. But that’s no indication that the fraudsters have gone straight. And as public investment in food safety analysis continues to be cut, we’d be impossibly naïve to imagine that the situation is destined to improve.

But then, we are impossibly naïve; and what’s more, it suits us to remain that way, because our chief expectations around food are fundamentally incompatible.

We expect to take pleasure from the food we eat; but at the same time, we expect to pay as little as possible for the privilege. And achieving both of those things at once depends to a great extent on the questions we choose not to ask, and the truths we don’t much care to think about.

When we eat a £1.99 portion of fried chicken and chips, it doesn’t suit us to consider the conditions in which the birds lived, or the drugs with which they were pumped in order to survive them. Deep down, we might have a fair idea of the grim reality; but at the moment of consumption, the truth would impinge unacceptably on the pleasure.

So it is with our “lamb” curry. We choose to believe it’s full of good-quality diced lamb, of the kind we see in our local butcher’s or supermarket – though when we compare the price of fresh lamb with that of the curry, it’s hard to see where the takeaway is making its money. But anyway, the meat looks like lamb – though admittedly it’s taken on the colour of its surroundings – and even though its flavour is overwhelmed by the curry spices, we’re still reasonably certain it tastes like lamb. But as a few of the Guardian’s writers recently discovered, our palates and expectations frequently conspire to hoodwink us. And so the opportunities for substitution and dishonesty are far greater than we’d care to admit.

What allows us consistently to enjoy the cheap food we eat is the same thing that lets us engage with a far-fetched book or film: our capacity to suspend disbelief. Our empathy with the heroic space warrior, taking down alien after alien with his trusty plasma gun, is contingent on our suppressing what we know perfectly well: that the entire scenario is utterly implausible.

This suspension of disbelief doesn’t only apply to the ethics of the fried chicken meal or the authenticity of the lamb curry; it applies to every aspect of food processing, from farm, to factory, to retailer, to restaurant. Every time our food passes through a different pair of hands, another opportunity arises for fraud, adulteration or corner-cutting to take place. And at every stage, we take great pains not to think about it.

Even when the “fraud” is entirely inconsequential, we choose to pretend it doesn’t happen, then become indignant when confronted with the reality. Anything that compromises our fantasy of what goes on in a professional kitchen – for instance, the common and harmless practice of food being prepared off-site and heated up on the premises – is sufficient to provoke our largely directionless outrage.

This is ludicrous. Face it: everyone involved in your food’s journey from origin to plate needs to make a living, legitimately or otherwise. And the more steps this journey involves, the more people need to get paid. Even if the final product seems remarkably cheap, they all have to make their money somehow. So the only way you’ll make actual rather than perceived savings, while reassuring yourself that nothing untoward has gone on, is by taking the various jobs on yourself.

The trouble is, not many of us are in a position to grow our own vegetables, catch our own fish, raise our own animals or even cook all of our own meals. So what are the alternatives?

At one extreme, we have the option of saying “sod it”. Buy whatever’s cheap and tasty, and simply accept the fact that we could be eating almost anything. To a large extent, this is what most of us do already; but when we do, we should at least have the balls to admit it, and not get affronted when we find out that our 3am kebab might contain something other than prime lamb.

At the other end of the spectrum, we can go all out to establish the provenance of our food – if we have the time and money. The simplest way to do this is to go organic: not particularly because of any inherent superiority, but because organic producers are required to submit to a regime of scrutiny, testing and animal welfare that goes way beyond any Government-imposed standards. (Tacitly, we appear to believe organic food to be more trustworthy, judging by the way we feed our children: organic produce accounts for only around 2% of overall UK food and drink sales, but the figure for baby food is a startling 54%.)

Between these two extremes, of course, there’s a substantial middle ground: it isn’t a straight choice between doing everything or nothing.

The more we cook for ourselves using fresh, unprocessed (or, at least, less processed) ingredients, the less risk we run of eating something unsafe or unexpected. The broader the range of foods we learn to cook, the better placed we are to eat with the seasons, enjoying ingredients when they’re plentiful and inexpensive (ironically enough, lamb is cheap as chips at the moment…).

The more we learn to use up spare or leftover food creatively, the less food and money we waste, allowing us to spend the savings on better quality ingredients.

And the more pressure we put on our politicians to invest in food testing and supply chain monitoring, the more chance we have of actually finding lamb in our lamb curry.