Heat oil in a pan kept on medium heat. Add onions and saute for 3-4 minutes, until they soften. Add tomatoes and fry them for another 3-4 minutes.
Lower the heat to medium-low and add the remaining ingredients - eggs, chilli, chilli powder, salt and coriander leaves and gently stir the mixture.
In about a minute, increase the heat and scramble the mixture to break down the clumps to the size you desire. Continue cooking till the eggs are done.