1)Heat oil in a pan or a kadai.
2)Splutter mustard seeds.
3)Add the grated ginger, garlic and curry leaves and saute for 3 mins, till its brown.
4)Add the powders and saute on a low flame for 1 min.
5)Add little water (1/2 cup) to this followed by kudam puli and required salt. Let it boil till half the water is evaporated.
6)At this point, you can add the prawns and let it be cooked on a low flame.
:- Make sure all water is evaporated.
7)Heat oil in another pan.
8)Add the red onions and saute, till its brown.
9)Add the thengakothu and saute it nicely.
10)After this u can add the cooked prawns and saute well till fried.
:- Try to use fresh prawns for tasty results.