Cover the dough with damp cloth and set aside for 15 minutes.
To make the filling
While the dough is resting, make the filling. Heat oil in a pan, add cumin seeds, carom seeds, ginger-garlic paste and saute for a minute.
Now add finely chopped onions, coriander powder, chilli powder, and salt. Saute till the onions are golden brown. Add chopped coriander leaves and switch off flame. Let it cool.
To make Kachoris
Divide the dough in to approximately 11 to 12 equal pieces.
Take one piece of the dough, shape them in to cup. Add a tsp of filling and pull the edges to cover the filling. Flatten the round in to flat discs. Repeat the above steps for other pieces of the dough.
Heat oil to a medium heat (the oil should not be very hot nor very cold. The indication is when you drop a small piece of the dough, the dough should not sink nor float up immediately but slowly sizzle up).
Drop the kachoris carefully in the oil. Let it cook one side, flip and cook the other side. Fry the kachoris till they are golden brown. Drain on a paper towel serve hot with tamarind chutney.