Tarka is technique where spices are added to very hot oil. When the spice seeds are added to the hot oil, they pop and sizzle bringing out the intense flavor and aroma.
Tarka might be done in different ways:
Its either done at the beginning of a recipe, and then the other ingredients are added to it. So its cooked in the seasoning and flavored oil.
It is also may be done after the dish is cooked. The spices are added to the hot oil, and when the Tarka is done, the oil along with the spices are poured over the dish, stirred and covered to retain and intensify the flavor.
Sometimes it may be done both at the beginning and the end.
Other names of Tarka: “Chhownk” & “Baghaar“