Its roots may lie overseas, but fish and chips become as potent a symbol of British identity as rain, the Beatles and a pint of bitter

If the Yanks are as American as apple pie, then we on this side of the pond are as British as battered fish and chips. And it is not just us who think so — the dish is inextricably linked to the Brits the world over, even as far away both culturally and geographically as China.

At Ultraviolet in Shanghai, an avant-garde "multi sensory” restaurant with a waiting list of months, there’s a homage to fish and chips. When the deep-fried delicacy arrives, the Union flag is projected on to the tabletop and glasses of ale are poured. And in case the guests haven’t quite clocked which country the restaurant is referencing, the Beatles play on the soundtrack while the walls are transformed into windows lashed with rain.

So when the social and food historian Prof Panikos Panayi made the claim that this bastion of our national cuisine is, in fact, derived from a Jewish recipe brought to our shores in the 19th century, it made headlines. One neo-Nazi website forum even put Panayi on a list headed "Know Your Enemy”. Unfazed, the professor started a book on the topic. Now, a decade later (academic research tends towards the slow-cooked), he has published Fish and Chips: A History, telling the story of the dish in Britain, from Victorian poor man’s streetfood to middle-class nosh-talgia, and with it a tale of immigration and entrepreneurship.

I meet the professor at Grimsby Fisheries, one of his favourite chippies in Leicester, where he lectures at De Montfort University. The premises on the Welford Road has been a fish and chip shop for 75 years, nearly 50 of them with the Eleftheriou family. It’s one half takeaway, the other eat-in, to my relief (call me unpatriotic, but while fresh fried fish and potatoes, hot and crisp, make for joy on a plate, wrapped in paper they’re a flabby, greasy, soggy mess – not my cup of builder’s).

We sit on the blue vinyl benches at a Formica-topped table in the window, with a good view of the pizza takeaway, the pie shop, the Chinese and the Indian restaurants across the road. Are eateries such as those the reason that fish and chip shops have declined from 25,000 in 1921 to less that half that number now? The prof, a softly spoken, dark-eyed, middle-aged man whose parents emigrated from Cyprus in the Fifties, is more inclined to look on the bright side.

In an age when large companies dominate the marketplace, "fish and chip shops have survived as largely independent concerns… which suggests the continued existence of an entrepreneurial spirit in Britain,” he says smilingly.

His optimism is echoed by the National Federation of Fish Friers, which points out that although many now sell Chinese, Indian, pizza or fried chicken alongside the fish and chips, the chippy still outnumbers McDonald’s by a factor of eight, and Kentucky Fried Chicken by a factor of 12. We spend £1.2  billion a year on fish and chips and 22 per cent of Britons visit every week, 80 per cent at least once a year.

We order from a menu decorated with classical friezes (the Eleftherious are Greek Cypriots, too), choosing simple fish and chips and a cup of tea. Meanwhile, the restaurant is filling, mostly with local retirees who hail each other as they come past the counter.

For all that it is embedded in our psyche, fish and chips is a relatively new addition to our diet. "Fresh fish itself was a luxury food for those not living near the coast,” Panayi explains. While church fast days, Fridays and Lent were times when fish was prescribed, for most it would have been salted or heavily smoked to preserve it. "Then in the 19th century the railways changed everything,” he adds, "speeding up distribution to make cheap fresh fish available to the working classes.”

The Jewish population were already adept at frying fish to preserve it, ready to eat cold on the Sabbath. This may be why, in the 19th century, with the arrival of bountiful fresh fish to the cities, particularly London, Jews became the main sellers of hot fried fish at street stalls, mostly using the leavings from Billingsgate Market, often small flatfish like dab, plaice or skate. The cook-owners dipped the fish in a batter of flour and water to protect it from the fierce heat of the fat – which would have had the added benefit of making the fish appear larger. It was cheap, nourishing food for the poor urban working class.

The fish was sold alone, or sometimes with a slice of bread. Potatoes came from another seller, generally baked. It wasn’t until the second half of the 19th century that potatoes cooked in the French style – cut into fingers — became common. No doubt it made sense to cook potatoes and fish by the same method, and by the 1870s working classes could buy fish and chips from street stalls and public houses, as well as fish and chip shops. By the end of the Victorian era, mass production made for cheaper standardised equipment and the fish and chip shop was a common sight.

The professor’s and my fish arrive, pieces as large as my forearm lapped by a lake of mushy peas and flanked by a mound of chips. There is lemon to squeeze over, which Panayi ignores, electing to douse his plate with malt vinegar. He grew up eating fish and chips regularly and still has them once a week. Does he make them at home? "No. I can’t see the point. I’d end up with something a bit less good than I can buy down the road.”

It makes sense to leave it to experts, especially since deep frying is smelly as well as messy (and potentially dangerous). And, generally, those experts were immigrants. After the First World War, Italians arrived and opened in Wales and Scotland (chef Angela Hartnett comes from a family of Italian fish and chip shop owners), and after the Second World War it was the turn of the Chinese and the Greek Cypriots.

The owner of Grimsby Fisheries, Lefteris Eleftheriou, known as "Lefty”, joins us. It takes dedication, he tells me. "I work every day. We sell 2,000 portions of fish and chips a week.” Good fish and chips, he says, is down to high quality fish (almost all theirs is fresh from Grimsby; they only resort to frozen when the weather or holidays disrupt supply) and the right potatoes.

"Potatoes vary through the year – some have levels of glucose that are too high,” explains Eleftheriou, a former biochemist. "Then they brown too quickly and are soft.”

None of his children is interested in taking over the business, he says, so he will sell it eventually. Most fish and chip shops in Leicester now are owned by the Asian community, the latest to take up the baton. It’s a progression that has mirrored our national embrace of foods from China, India, Italy and beyond. So while the fish might be Jewish and the chips French, the combination is as British as rain, the Beatles and a pint.