Last year I gave a speech on Indian food at the French Embassy in Washington, D.C. and mentioned that I used garlic in my mustard-fish curry. An older lady approached me afterward, very upset. She had never heard of garlic being used in mustard-fish curry. How dare I spread myths about Indian food? I was really taken aback. My mother did it that way, I explained to her. My mother's mother did it that way, and we assumed my great-grandmother did it the same way. But no explanation would appease her.

Now, people often complain about the arrogance of the young, but still I had to wonder: how did she know that her recipe was authentic and mine was not?

One of the most popular Indian dishes in Britain is chicken tikka masala, a dish of marinated, clay oven-roasted chicken simmered in tomato sauce. Estimates are that as many as 23 million portions a year are sold in Indian restaurants in England alone. But there is absolutely no evidence that chicken tikka masala came from India. Its origins are in some dispute (England? Ireland? 1950s? '60s? '70s?). The most popular origin legend is that in the 1970s a British chef poured Campbell's Tomato Soup over some leftover chicken tikka (marinated chicken pieces cooked in a tandoor), called it Chicken Tikka Masala—and the dish became a sensation.

In 2001, Britain's foreign secretary called chicken tikka masala Britain's national dish. Does that make it authentically British?

What does authentic really mean? Who decides what authentic is?

India is famous for its tomato-based curries, yet tomatoes were not even introduced into Indian cuisine until the 16th century (at the same time as potatoes). Chiles weren't in Indian cuisine until sometime during the 15th century—amazing, considering authentic Indian food is said to be hot and spicy. Authenticity, it seems, evolves.

To avoid any further annoying exchanges on the subject I decided no longer to use the phrase "authentic Indian" to describe a dish. I began to use "traditional." But inevitably I encounter self-proclaimed standard bearers who run after some marker of "authenticity" (my mother made it that way, I tasted it this way, the superstar chef makes it this way) that may or may not have relevance to other people.

Years ago, when I first moved to the States, I hosted my first dinner. My friends requested authentic Indian food and I tried my best to comply. We had cumin-scented potatoes, a shrimp-coconut curry, a vegetable pilaf and several chutneys and pickles. Everyone loved the food but then came the dessert: custard with fruits. "So you didn't want to make an Indian dessert?" one friend remarked.

I was taken aback—how could a dish I had learned at the knee of my grandmother and perfected under my Indian mother's watchful eye and eaten and served at almost all large family gatherings not be Indian? "I suppose," he went on, "this is a remnant of what the British may have left behind in the Raj."

Perhaps he was right, that my grandmother or her mother had learnt to prepare it during the British stay in India. But to me, custard with fresh fruits is as authentic and traditionally Indian as chicken curry. Authenticity and tradition are born out of personal experience of the home cook and from the embrace of environment. Restaurants don't factor in because their menus are designed to cater to specific markets.

There is nothing wrong with learning about the history of a dish and its origins. The problem comes when that curiosity overrides common sense; when strict adherence to the "authentic" becomes rigid, judgmental and a general pain in the ear; when having a dish denounced while you're enjoying it muddies the experience.

When I worry obsessively about something, my father reminds me an old Indian saying: "Aam khao, ped kyon ginte ho?" Translated literally, it means: Enjoy your mango and don't worry too much about which particular tree it comes from.

Monica Bhide is the author of The Everything Indian Cookbook: 300 Tantalizing Recipes—From Sizzling Tandoori Chicken to Fiery Lamb Vindaloo.