A good way to get to know a city is through its food.

On a recent trip to London, I joined the locals and queued for 20 minutes at Borough Market for Ethiopian food. I figured that if office workers from the area were willing to spend a chunk of their lunchtime waiting for it, the food must be good. It was, and I'm now a fan of Berbere spice and the aromatic butter Nit'ir Kibe that Ethiopians use to flavour their food.

Middle Eastern food is trending in London and a visit to tiny, bustling Honey & Co - set up by a pair of Israeli chefs who have become local celebrities - has me dreaming still of the dessert they served that day: spiced chocolate cake with coffee cream and milk.

For two years running, Londoners have chosen Dishoom as their favourite restaurant, according to crowd-sourced review site Yelp.com. Dishoom serves good Indian food - black daal, biryani, chole bhatura and more. The interiors of its restaurants pay homage to the Irani cafes that were once part of the Mumbai scene. They do not take reservations and the wait on a Saturday night is an hour long, but waitresses come by with small glasses of chai and sherry to make it more bearable.

After a week of indulging in immigrant cuisine, I finally made it to a restaurant that serves British food. In business since the 18th century, Wilton's had been, by some accounts ,Winston Churchill's favourite place for lunch. I had been craving bread and butter pudding and was overjoyed to finally see it on the menu.

London's exciting dining scene reflects the city's diversity. Well over a third of its population are foreign-born. The Greater London Authority's 2001 census found people of 179 nationalities living in Britain's capital, which also happens to consistently come up tops in Global City indices.

A 2015 survey of top-performing cities by management consultancy A. T. Kearney, for instance, puts London in second spot behind New York, based on five dimensions: business activity, human capital, information exchange, cultural experience and political engagement. These measures were chosen, A. T. Kearney said, because the mark of a great city is its ability to attract and retain global capital, people and ideas. Singapore placed eighth, behind Paris, Tokyo, Hong Kong, Los Angeles and Chicago and just ahead of Beijing.

The chefs behind Honey & Co are a good example of London's ability to draw people and make them stay. In one interview, the married couple described their move to London as "a food decision".

"We came here to improve our cooking, to be exposed to new things. Israel has great food but it's Israeli food. Coming here opened us up to Asian, Indian, European food," says wife Sarit Packer, a pastry chef.

Her husband Itamar Srulovich adds: "The plan was to travel around Europe, cooking in different cities, but we didn't make it further than London."

The "world in one city" is the London authorities' preferred slogan which they used to good effect in their successful bid to host the 2012 Olympics, suggesting that "our multicultural diversity will mean every competing nation in the Games will find local supporters as enthusiastic as back home".

In 2005, the Guardian newspaper celebrated its hometown as "the most cosmopolitan place on earth" and wrote that "never have so many different kinds of people tried living together in the same place before".

Professor Steven Vertovec, director of the Max-Planck Institute for the Study of Religious and Ethnic Diversity, has even coined a special term to capture the complexity to be found in a city like London: super-diversity.

Super-diversity, he writes, underlines the dynamic interplay of variables that characterise immigrants and influence integration. These include country of origin, and within that, a subset of traits such as ethnicity, language, religious tradition, regional identities, cultural values and practices. Then there's migration channel, which is often tied to gender, specific social networks and particular labour market niches. There's legal status, as migrants fit into a myriad of categories that determine what they are entitled to and the restrictions they face.

These variables influence integration outcomes, along with other factors such as migrants' educational background, access to employment, where they live and the response of the local authorities, services providers and residents, writes Prof Vertovec.

This is how London's modern art museum, the Tate Modern, summed up the challenge of diversity in a 2007 exhibition on Global Cities: "In an urban context, diversity - the level of variety within a city - is usually interpreted as its ethnic and racial composition. But diversity has a much broader range of indicators: the spread of ages and incomes, education levels, the range of employment sectors, and people born in the city versus newcomers.

"When cities grow to accommodate new people, they test the human capacity for coexistence, whether the newcomers are from outlying rural areas or the other side of the world. Diversity can affect a city's social cohesion in different ways. It can foster a degree of integration amongst people from diverse backgrounds, celebrating tolerance and coexistence. On the other hand, it can equally engender segregation, with diverse groups coexisting separately, leading to a potential for social conflict and confrontation."

Unlike London, the level of diversity in Singapore has yet to reach super levels. But London's experience highlights the need for a more nuanced approach to integration, taking into account the complexity of factors at play.

What is certain is that multiculturalism will increasingly be a defining feature of the world's great cities. Or as cities expert Michael Keith predicted in his 2005 book After The Cosmopolitan?: Multicultural Cities And The Future Of Racism, "the cities of the 21st century will increasingly be characterised by the challenges of multiculturalism".

One key challenge is economic competition, which continues to shape attitudes towards newcomers. In a report on cohesion in Britain, Prof Vertovec said academic studies made clear that "inter-relations are closely dependent on the existence or absence of competition for local resources and services".

"Lack of conflict between ethnic groups is often due to a separation of communities by way of economic niches, and/or differential demands on public resources... as deprivation increases, there is a fall in the number of people who agree that people from different backgrounds get on well together, and a fall in the number who agree that residents respect ethnic differences between people," he notes.

That leads him to conclude that "inter-ethnic or immigrant-'host' relations may be underpinned by anxiety or a sense of threat if there is perceived competition for resources, including jobs, education, housing, welfare benefits and other forms of public largesse".

Globalisation is a force that brings both perils and promise.

The stratification that comes with being a global city is real and Singapore must act to mitigate it. The Government's work to craft and implement policies to ensure a fairer distribution of resources and safety nets for the vulnerable must continue.

As for Singaporeans' fears of being swamped by foreigners and having to compete with them for jobs and university places, these are valid and need to be addressed.

But such fears must not overshadow the positives that come with welcoming migrants. They are the lifeblood of cities, bringing with them fresh ideas, and injecting energy and vitality.

Singapore has harboured global ambitions from its birth and cannot afford at the age of 50 to give up on this dream.

It must fight to remain a leading global city, a hub of opportunity for long-time residents and newcomers alike, with an amazing food scene to match.