If you visit Indian restaurants, you almost certainly know someone from Sylhet. The vast majority of British curry houses are run by Bengalis, and most of them come from this small area. They provide us with the rogan josh, chicken tikkas, tarka dhals and onion bhajis that have become a second national dish. For Indian restaurants are a peculiarly British institution - while Chinese cooking is available worldwide. Ask the right sort of expatriate Briton (urban, middle class) what he misses most about home and like as not he will mutter about curries. It is often said that you can get a better Indian meal in London, Birmingham or Bradford than in Delhi or Dhaka.
Indian (or rather Bangladeshi) restaurants are big business. The 10,000 curry houses in Britain turn over pounds 1.5bn between them and employ between 60,000 and 70,000 people - more than steel, coal and shipbuilding combined.
In theory, the future of the curry house is rosy. The market for ethnic food overall almost doubled between 1990 and 1994, and research shows that customers at Indian restaurants are both younger and more affluent than those at their Chinese rivals. Ever since the Seventies curry houses have been struggling to throw off their "vindaloo after closing time" image - and most have succeeded.
But the reality is somewhat different. Increased competition combined with a tight-walleted population means that curry houses are no longer the toothsome businesses they once were. A survey by the Leatherhead Food Research Association also comes up with a worrying trend: Indian food is lagging behind Chinese in popularity. More than half the respondents said they intended to eat more Chinese food, while none said they would eat more standard Indian grub. Only Balti, a relatively new variation, showed signs of life.
Mohammad Shanjab is owner and chief cook of the Curry Cabin, a small restaurant in south-east London. He came from Sylhet with his parents in 1971, when he was 15. Two years later he became a trainee cook at the Curry Cabin, then the only Indian restaurant in the area. The owner took to him and in 1978 sold him the business. Since then he has been providing a rich and consistent taste to those who like their Indian restaurants traditional - no flock wallpaper, but plenty of red plush and oriental imagery.
The good times rolled from the mid-Seventies until 1991. Then the recession and the Gulf War slammed in and flattened the market: it has yet to recover. "I haven't been able increase my prices for the last four years," Mr Shanjab complains. He has also had to start free home delivery to fight off the take-aways. "I'm surviving," he says. "But it is not as profitable as before." His problems have not been eased by the competition, which has continued to grow. The area now has eight Indian, three Thai, two Chinese, one Mexican and one French restaurant, as well as chip shops and take- aways.
Hussain Ali, the Curry Cabin's head waiter, is even more pessimistic than his boss. "People think we're in a good business, but it's very bad nowadays," he says. "It used to be busy - now it's terrible."
Ashraf Uddin, organising secretary of the Bangladesh Caterers Association, confirms that these problems are typical. "It's quite difficult to make a profit because the recession is still on," he says. His association is concerned that some curry houses have been driven to offering half- price meals. This will affect the quality of the food, it says, and "will bring a bad name to our prestigious cuisine".
The best hope for the industry lies in the enterprise of the restaurateurs and their adaptability. In the Curry Cabin's kitchen is a clay Tandoor oven, in which tikkas and naans are made. The Tandoor is not part of the Bengali cuisine - it comes from north-west India and Pakistan - but a restaurateur tried one out in the Sixties and found himself with a hit. Before long, a mass of Bangladeshi restaurants were reborn as Tandooris. Now some Tandooris are in turn becoming Baltis - selling dishes whose origins lie in Afghanistan. It is something of a con, it seems. "Baltis are not really any different from our cooking; they just change some of the spices," Mr Uddin says.
Some small chains have been built up, mainly by second-generation immigrants. But the great majority of restaurateurs are rubbing along much as they always have done - one family owning one restaurant. This fits with the Bangladeshi tradition of self-reliance that lies behind the industry's past successes.
A scattering of Indian restaurants appeared in Britain many years ago: the Salut-e-Hind, founded in 1911 in London's Holborn, is believed to be the first. But the foundations of today's industry were laid in the Forties. The people of Sylhet had strong links with the UK because of the tea trade, and many of them joined the British army or merchant marine when war broke out. Some then settled in London, and wondered what to do.
There was no great culinary tradition in Sylhet but, Mr Uddin says: "When they came here they lacked education and found English very difficult. But they were mostly self-employed at home, so they were used to running their own businesses." He believes the first Sylhet restaurant was the Greenmarks, founded by Mashraf Ali in Tottenham Court Road, London in 1943. By 1960 there were 1,000 restaurants run by people from the area - then in East Pakistan - and when the country seceded to become Bangladesh in 1971 there was another wave of immigration. The easiest business for them to enter was the Bengali-speaking restaurant industry.
Although there are different types of Indian restaurants (vegetarian from the the south, Gujarati, Punjabi), Sylhet still dominates the curry industry. A steady flow of new immigrants supplies the labour market - which is why it is rare to find a waiter who has completely fluent English.
Hussain Ali's story is typical. His father came to England in the Fifties, working first in a brewery then in a factory in the Midlands. His wife stayed in Sylhet and Mr Ali, who was born in 1967, hardly saw his dad until the whole family moved to England when he was 14. "We were very poor and I didn't have much schooling," he recalls.
He was sent to live in Kendal with a cousin; as the only Asian in a school of 500 he learned English quickly. Then
he came to London and found work as a waiter in Brick Lane, a centre for restaurants in the East End. Four years later, he was approached by a man who came from a neighbouring village in Bangladesh; he ran the Surma restaurant in south-east London, and Mr Ali left to work for him. After a while, Mr Shanjab popped in and asked him if he knew any good waiters. He was offering more money, so Mr Ali moved down the road to the Curry Cabin.
Five years ago, he was married to a girl who originally came from his home district, but who was living in England. "My auntie in Birmingham arranged it," he says.
The arranged marriage is critical to the industry because it ensures an influx of potential waiters. Mr Ali hopes that his son, four-year-old Faizzal Hussain, will not be a waiter ("the hours are so long") - and, with a British education and fluent English, it is unlikely he will be.
That means the curry houses need a steady supply of immigrants to staff them - and this is where the marriage comes in. If a Bangladeshi couple have a daughter in Britain, they will at some stage look for a partner for her. They may find one locally; more likely they will ask an aunt or friend in Sylhet to keep an eye out. The chosen young man will then travel to Britain where, with his limited English he will, like as not, have to take a job in a restaurant.
Few people would be waiters by choice. Mr Ali works a split shift, from 11am to 2.30pm, then 6pm to midnight, six days a week. He gets home to Wapping about half past midnight; his wife has his only meal of the day ready. His pay is "OK", he says, but he gets only two weeks' holiday a year. If he had the choice, he says, he would rather work in an office. "But I can't because my English is not good and I'm not educated." Finding a job as a waiter, by contrast, is not difficult - he could use his personal contacts, specialist agencies or even the Yellow Pages to seek out employers.
Indian - or rather Bangla-deshi - restaurants have improved immeasurably in quality, but they still have difficulty differentiating themselves from each other. Not having flock wallpaper was once a handy trick - now it is the norm. Baltis, once unusual, are already common. And it seems that any new gimmick that is thought up spreads so fast among the adaptable Bangladeshis that it quickly loses its profit-spinning appeal.
The restaurateurs are, in that sense, the victims of their own ability. Unless consumers are prepared to unzip their wallets, it seems that consolidation and closures are inevitable. Bad news for tikka-loving consumers; good news for Mr Shanjab and his balance sheet - but only if he emerges as one of the survivors.