The name is the least stable part
Ask for a rasam in two towns a few hundred kilometres apart and you may get two soups with different bases, different souring agents, different consistencies and different roles in the meal. The same is true of kadhi, of pulao, of a dozen things called curry, and of almost any dish whose name is old and widely used. The name has travelled; the recipe has not.
This causes endless low-grade argument online and it is worth being clear about the underlying situation. There is generally no original version being corrupted. What exists is a family of related preparations that share a name because they share an ancestor or a function, and which diverged as they met different ingredients, different staples and different climates.
What changes first when a dish moves
The souring agent almost always changes, because it is the ingredient most tightly bound to what grows locally. A dish soured with tamarind in one place will be soured with kokum, raw mango, lime, yoghurt, tomato or dried fruit somewhere else, and the whole balance of the dish shifts with it because each of those brings sweetness, colour and body in different amounts.
The cooking fat changes second, for the same reason. The third thing to change is the level of heat and the source of it, which tracks local preference and local varieties. What tends to survive longest is the structure of the dish — the sequence of operations, the consistency it is meant to reach and what it is eaten with — because that is tied to the meal rather than to the market.
This gives a useful way to read an unfamiliar regional version. If the structure matches and only the ingredients differ, it is the same dish adapted. If the structure differs too, it is a genuinely different preparation that happens to share a name, and expecting it to taste like the version you know is a mistake.
The staple decides the consistency
The most reliable single predictor of how a dish will be adapted is what it is eaten with. A preparation moving into rice country becomes thinner, because a thin liquid soaks into rice and a thick one sits on it awkwardly. The same preparation moving into flatbread country becomes thicker, because bread has to pick the food up.
That one constraint explains a great deal of variation that otherwise looks arbitrary. It is why the same ground name covers a soupy dish in one state and a nearly dry one in another, and why the quantity of liquid in a regional recipe is frequently the thing that surprises a cook from elsewhere the most.
Portion structure follows. Where a meal is several small dishes around a large quantity of rice, individual preparations are stronger and more concentrated because they are eaten in small amounts. Where a meal is two or three dishes with bread, they are milder and there is more of each. Neither is a matter of taste preference in the way it is often described.
Migration complicates the map further
The neat regional picture is disturbed constantly by people moving. Communities that relocated carried their cooking and then adapted it to what was available where they arrived, producing versions that belong to neither place entirely. Trading communities, in particular, left recognisable culinary traces along the routes they used, and those traces do not respect state boundaries at all.
Restaurant cooking has added another layer over the last several decades. A restaurant style that became popular nationally can travel back into home cooking and displace a local version, so a dish someone grew up with may itself be a recent import rather than an ancestral one. This happens quietly and is rarely noticed by the people it happens to.
None of which makes regional identification useless. It makes it a description of tendencies rather than a set of rules, and the honest way to talk about it is with a fair amount of hedging.
Cooking from a regional recipe you did not grow up with
The practical advice that follows is to pay attention to structure and treat the ingredient list as more negotiable than it looks. Getting the consistency, the sequence and the balance right will produce something recognisable even with substitutions; getting the ingredients exactly right while missing the consistency usually will not.
It also pays to find out what the dish is eaten with before deciding it is too thin, too sour or too salty. A preparation designed to be eaten in small quantities with a lot of rice is supposed to taste too strong on its own, and judging it by the spoonful is judging it out of context.
And where two versions genuinely conflict, the reasonable response is to pick one and cook it properly rather than averaging them. An average of two coherent traditions is usually less good than either, because each was internally balanced and the blend is balanced against nothing.
Common questions
Which regional version of a dish is the authentic one?
Usually the question does not have an answer. Most widely spread dishes are families rather than single recipes, and the versions are all authentic to somewhere. What can be said is which version belongs to which place, which is a more useful thing to know.
Why do restaurant versions taste so similar across the country?
Restaurant cooking converged on a small set of base gravies that can be produced in bulk and finished to order, which is an efficient way to run a kitchen. The result is a national restaurant style that is genuinely its own tradition, and it is not the home cooking of anywhere in particular.
If I substitute the souring agent, is it still the same dish?
By the standard applied here, mostly yes, since that is exactly the substitution regional variation makes constantly. Expect the balance to move, though — different souring agents carry different amounts of sweetness and body, and the rest of the seasoning usually needs adjusting to match.
Editor, Wah Taste
Sanaya has written about everyday cooking, street food, spice & pantry for most of the last decade and prefers a plain explanation to a clever one.
