Heat the oil in a wide pot over a medium flame. When hot, put in the minced onions and garlic. Stir and fry until the mixture is a rich medium brown shade. Turn heat to medium low and add the coriander, cumin, (NOT the roasted cumin), cayenne, and turmeric. Stir for a few seconds. Now put in the finely chopped tomatoes. Stir for a few seconds.
Now put in the finely chopped tomatoes. Stir and fry until the tomatoes are well amalgamated with the spice mixture and brown lightly. Add the drained chickpeas and 1 cup water. Stir. Add the ground roasted cumin, amchoor, red pepper, garam masala, salt, and lemon juice. Stir again.
Cover, turn heat to low, and simmer for 10 minutes. Remove cover and add the minced green chili and grated ginger. Stir and cook, uncovered, for another 30 seconds.