Although ostensibly a means of securing sustenance and pleasuring the palate, food often has the capacity to bring out the nationalist in people. Regard the manner in which the French boast of their excellence in the kitchen, haughtily deriding the Americans for their sorry excuse for a national dish: McDonald's. Witness Italians sneer at the imitation pizzas found in Britain and the US, or how Indian visitors recoil in horror from menus found in curry houses in the UK, with their strange, mangled neologisms. Food can be a source of pride, and it can thus be distressing when restaurants tamper with national dishes.
Gastronomy continues to be a source of anxiety. Earlier this month Terence Conran made known his displeasure at the barbarisation of restaurant menus in Britain, excoriating the proliferation of "franglais" gibberish. The restaurateur David Tang has since expressed his own concerns about the state of Chinese food here, lamenting "chop suey" and "foo yung" as "ridiculous" inventions of the 1960s.
It is odd how cooking brings out the Platonic essentialist in culinary connoisseurs. After all, one of cuisine's defining features is its capacity to evolve and innovate, with one culture appropriating a dish from another and fashioning something entirely new from it. What is more, the idea that there is such a thing as a "traditional national" dish is phoney, first because many of them are borrowed or adapted from elsewhere, and second because the idea of "authentic" national food is just as erroneous as that of an "authentic" national culture.
Consider the pizza. In 2004 the then Italian ambassador to the UK, Luigi Amaduzzi, complained about the fare being served in Britain in his country's name. "A pizza base covered with pine-apple or with curry is no more Italian than a steak-and-kidney pie covered with chocolate is English." To Italians, a pizza simply consists of flat bread, tomatoes, mozzarella and basil. Although some claim that the pizza dates back to Roman times, tomatoes are a New World fruit, and the pizza as we know it may not have been invented until the 18th century - which is before the creation of the Italian state itself.
Other "traditional" Italian dishes are even more suspect. Fettuccine primavera was invented in New York. So was chicken tetrazzini. And caesar salad and spaghetti with meatballs are similarly American creations. As one observer put it: "By the 1950s Italian-American food was all but unrecognisable to visitors from Italy. A businessman from Turin might peruse a menu in an Italian restaurant in Chicago and not be able to decipher a single item." Chop suey is indeed a recent invention, emerging from San Francisco in the late 1880s, and there is little that is historically Chinese about the fortune cookie or chow mein, both devised in the US in the early 20th century.
England's "traditional" dish is an im-ported hybrid. It became popular in the late 19th century, when workers decided to marry the Belgian/French custom of frying chipped potatoes with the immigrant Jewish tradition of deep-frying fish in batter. Fish and chips has since been superseded by chicken tikka masala, another recent concoction. For many years, we had all assumed tikka masala to be a genuine import from the sub- continent, but now we know its defining ingredient to be tomato sauce.
Why do many people find culinary contamination so discomforting? It is be-cause such cross-fertilisation threatens our sense of nationhood. All nations need artefacts to provide the illusion that theirs is a static, tangible and hermetically sealed entity, and food is invariably employed in this equation. The likes of fish and chips, steak-and-kidney pie, "British beef", "a full English breakfast", Marmite, tea and Yorkshire pudding are held to be cultural signifiers of Englishness. This is why the BSE crisis was considered such a national humiliation: "British beef" is John Bull's national dish. Nestle's takeover of Rowntree in 1988 and this month's collapse of the crisp manufacturer Golden Wonder are lamented for the same reason.
Cuisine and nationalism are intimately bound. Roland Barthes wrote: "Food brings the memory of the soil into our very contemporary life . . . food permits [the Frenchman] to enter daily into his own past and to believe in a certain culinary 'being' of France." The Englishman searching for a pie-and-mash shop at a Spanish resort and the Australian in London trying to find a jar of Vegemite are not merely looking for familiar foodstuffs: they are looking for food that reminds them what country they belong to.
Those who believed tikka masala to be Indian may have been misguided, but purists who deride it as an abomination are missing the point. The idea that some foods are authentic and others are not is bogus. To label a collection of meat and vegetables "authentic" is merely to claim: "This is a national dish because I say it is." We cling to this concept only because we are attached to the ideal of cultural essentialism. But cultures always change and innovate, borrow and mix facets from each other. And this includes recipes.
Patrick West is author of The Poverty of Multiculturalism (Civitas)