While tracing the evolutionary path of boiled grains to steam cooked idlis, it occurred to me that other tribes in the northwest
Dry roasting must have been popular in the early days of civilization, derived from the primeval habit of roasting meat over fire. The cultivation of the grains, logically lead to grinding of the grains and making a batter out of it. The batter was fashioned into a flat cake and roasted on the fire over the oven. Then probably the oil was not yet invented. Thus the early oil free tandoor roti was born.
The roti-roasting habit has also traveled to places. While wheat was the common staple food in northern
Note that even the rice rotis (kori rotti etc) common in coastal Tulunad, it is similarly dry roasted types.
Therefore, I feel oil was not used extensively in cooking in the early days of civilization. Probably vegetable oils were used for lighting lamps in the beginning, rather than for cooking. After introduction of the oils in cooking, it appears that til oil was common in usage in drier regions like northern Karnataka, while coastal people, where coconut trees abound, were consuming coconut oil.
I hope this partly answers Manjunath’s query on usage of oils in northern Karnataka before the introduction of ground nuts some 500 years ago.