Food writer Chitrita Banerji met her culinary nemesis on a trans-Atlantic jumbo jet. It looked innocuous enough, wrapped in its aluminium foil and still steaming from the blast oven, but this rendition of chicken tikka masala ended up being more than just a warmed-up, inadequately spiced airline meal; it turned out to be the seed of an idea for her next book.

The provenance of a dish like chicken tikka masala – probably invented by Punjabi restaurateurs for foreign palates, and now near-ubiquitous in ‘Indian’ restaurants the world over – got her thinking as she sat captive on that flight from London to Calcutta. How authentic is this trans-cultural dish? And what is authenticity anyway?

Questions such as these are what motivate the best food writers. The Calcutta-born writer is regarded as the world’s foremost authority on Bengali food and author of several classic works on Bengali cooking. She grew up in a well-to-do Hindu Brahmin household and food played an important part in her life. Banerji describes her family as being ‘absolutely obsessed’ with food. ‘Food was such a big part of our internal dialogue,’ she says. ‘I always found it very strange when I visited other families and nobody bothered about food and people ate very indifferently cooked food without caring. Their mothers never went into the kitchen; the servants did everything. My mother was a full-time school teacher but she still did most of the cooking because it was serious stuff.’

Banerji was born in the fateful year of 1947 (the year of the Independence of India and the Partition of India and Pakistan) so she is no stranger to privation, which she experienced first-hand growing up in Calcutta. She says, ‘It’s hard to remember these things now in big cities in India but in the late 50s and 60s there was a food shortage. Now people may complain that food is expensive, but I remember in my childhood and in my teen years, we had ration cards.’ Decades later, Banerji lived for a few years in newly independent Bangladesh, where she also witnessed large-scale hunger.

At the age of 20, Banerji moved to Cambridge, Massachusetts (where she still lives) on a scholarship to Harvard to study for a Master’s Degree in English. As is the case with many food writers, the sense of displacement that’s part of the immigrant experience was formative. She says, ‘I’m sure that a sense of nostalgia and sense of loss fuelled my writing. I know that when I’m writing, in my mind I’m always trying to recapture something.’

Before researching Eating India, Banerji was, in her own words, ‘a shameless champion of regionalism’ in cooking. A recognised expert on the food of her native West Bengal, Banerji admits that she ‘scoffed at the mere mention of “Indian” food or curry powder’ that she came across in her adopted country, the US. Yet, having spent time researching medieval narratives for her previous books, she was also aware that the Bengali food from her remembered childhood in Calcutta was very different from the food described in those ancient texts. The cuisine had changed over time, absorbing outside influences and ingredients. So, again: what is authenticity?

This is one of the questions she set out to answer in Eating India. In this book, Banerji widened her scope to cover regions as disparate as the Punjab, Gujarat and Kerala, and also explored the foodways of distinct groups such as the Jews of Cochin, the Anglo-Indian community of Calcutta and the indigenous tribal peoples of India’s Northeast. It’s part travelogue, part food book, part personal journey, written with the born storyteller’s ability to flesh out the story with colour, personality and an abundance of carefully observed detail, picked up and fleshed out during her half-dozen research trips.

Banerji may have set out in search of ‘authenticity’, but she soon realised that the idea was an illusion. ‘Authenticity is time-bound,’ she concludes. ‘How authentic can anything be? Some ingredients that we use now wouldn’t have been used 500 years ago. The ‘authenticity’ debate isn’t worth it; it’s always a work in progress.’ The trans-cultural, world-conquering chicken tikka masala is a perfect case in point – food for thought next time you encounter it on an ‘Indian’ menu.

Eating India is out now.