Wash the prawns with salt water.
Marinate the prawns with 1 tsp of ginger paste, 1 tsp of garlic paste, 1 tsp of red chilly paste, 1/2 tsp of mustard oil, turmeric powder, salt to taste, finely chopped coriander and whole garam masala powder for 10 mins.
Heat oil in a pan.
Splutter mustard seeds.
Add finely chopped onions.
Fry the onions, till they turn golden brown.
Add tomatoes, 1 tsp of ginger-garlic paste, soya sauce and red chilly sauce.
Add the marinated prawns and fry it for a minute.
Add water for consistency of a gravy.
Cook for 5 mins.
Garnish with coriander leaves.