"Curry is not only among the world’s most popular dishes; it also may be the oldest continuously prepared cuisine on the planet," according to Washington State University researchers Arunima Kashyap and Steve Weber. Working in the remains of an ancient city along the Indus river, they used modern molecular and archaeology techniques to identify residue from cooking pots as much as 4500 years old and discovered residue from ginger, turmeric, garlic, rice and other grains, and chicken. A Slate article dated last Tuesday, The Mystery of Curry, explains their findings.
"Kashyap used what is known as starch grain analysis. Starch is the main way that plants store energy, and tiny amounts of it can remain long after the plant itself has deteriorated. If a plant was heated—cooked in one of the tandoori-style ovens often found at Indus sites, for example—then its tiny microscopic remains can be identified, since each plant species leaves its own specific molecular signature." In addition to cooking residue, the research team examined the teeth and bones of humans and animals from the archaeology dig, which also provide evidence of the same foodstuffs being consumed.