I don’t expect your sympathy. There are, I concede, more deserving causes than ‘hack forced to eat sub-standard food in tatty restaurant at someone else’s expense’. Trust me on this, though: such suffering is yours at one remove.

The restaurant critic of the Sunday Telegraph, Matthew Norman, recently reviewed Shepherd’s, a restaurant in Westminster. He didn’t just review it; he damned it. “Where do you start with somewhere like Shepherd’s? You don’t. If you have any sense you finish with it.” Referring to his crab and brandy soup, he argued that “were it found today in a canister buried in the Iraqi desert, it would save Tony Blair’s skin”. The restaurant was “the eighth circle of hell”. Last week, the owner of Shepherd’s, Richard Shepherd, responded by threatening to sue the critic for libel, supported by its customers’ paeans of praise.

I wouldn’t want to rain on Mr Norman’s parade, but it is beyond me how anyone with a functioning sense of taste or smell could conceivably enjoy Shepherd’s. The food – food only in the sense that it is something which one puts into one’s mouth – is often disgusting and never, in my experience, better than barely acceptable. The atmosphere is like a public school dormitory for grown ups.

I speak with some authority. For nearly a decade I ate in Shepherd’s at least monthly, often more frequently. No, I am not clinically insane. But when I worked in Westminster, it was pretty much the only restaurant in the area. MPs and ministers would not want to venture far beyond, and so we would end up going to Shepherd’s. Dear reader, I suffered.

Shepherd’s is, of course, far from alone in serving dreadful food at an exorbitant price – two courses at lunch for £24. Pied a Terre, on the other hand - one of the finest restaurants in the country - charges just £21.50. It’s a paradox of which anyone who eats out is aware: pay two pounds fifty more and leave feeling sick; pay two pounds fifty less and eat some of the best food of your life.

It’s a paradox with an explanation, however. And that explanation is one of the oldest maxims around: you can indeed fool most of the people, most of the time. For a while I was a food critic, and the phenomenon which struck me most forcefully was that people really do think that price equals quality. Pay fifty pounds for a meal and it must be good. If you don’t like it – if it seems to you that the fish hasn’t been cooked properly or if the fruit tastes off - then it’s you who’s at fault, not the chef. You clearly don’t appreciate the originality of the kitchen.

I was recently served a rancid piece of cheesecake at a well-regarded restaurant. When I sent it back, not only was there not a word of apology, but initially the waitress implied that I clearly had no idea what cheesecake tasted like. ‘No one else’ – the classic line – ‘has complained’.

I used to cook for money (I hesitate to call myself a chef, since it was minor league stuff – I earned money as a student by cooking dinner parties) and cook almost all my meals at home. I’m not especially good – I just learned early on how to do the basics. So I’m not boasting, merely stating a fact, when I say that much of the food I eat out is no better than my own cooking. Nor should it have to be – the golden rule is to buy as good quality ingredients as you can find, and to do as little to detract from their flavour as you can. That should apply both in one’s own kitchen and in most restaurants. You don’t always want ‘fancy’ food when you eat out – more often than not you just want tasty food, properly cooked. And that really shouldn’t cost the earth. There is a brasserie at the end of my street in Brussels which serves the most delicious steaks, and perfectly acceptable claret, for 15 euros. No one wants to eat Michelin starred food all the time. When I do, I’ll pay for it.

There are two main problems with British restaurants. First, mid-range places tend to have grotesquely over-inflated prices. Even if Shepherd’s food was perfectly well cooked, the nursery-school menu should not cost more than the likes of Pied a Terre.

But worse still are the cheap and certainly not cheerful brigade – the Garfunkels, Pizza Huts and other chains - which seem economical but, since they serve pigswill, are quite as much of a rip-off.

You don’t always get what you pay for. I’ve had – who hasn’t? – dreadful meals in ruinously expensive places, and superb food in the most basic and cheap establishments. Just as you can get succulent, wonderful and cheap fruit in a local market, and bland, expensive rubbish in Harvey Nichols Food Hall, so too with restaurants. What you do get is what most Brits’ refusal to take food seriously allows Shepherd’s and Garfunkels to serve. If they had no customers, they would go bust. It’s that simple.