Heat oil in a pan and when it gets hot add mustard in to it.

When it splutters add onion, green chilly and curry leaves to it.

Saute it well and add pepper powder to it ,stir well.

Then add cauliflower to it and saute it well.

Then add little water and salt to it.

Then close the pan and wait until it gets cooked.

When it gets cooked and all the water gets vapourised , transfer to the serving dish.