Over medium heat, heat the cooking oil in a large saute pan.
Add the paste to the pan. Stir until the paste has thickened, and the fragrance of the paste is released.
Add the tumeric powder. Stir until well-incorporated.
Cover with a lid and allow to cook for 10-15 minutes.
Add tamarind water and continue to stir until well-incorporated.
Add sugar. Continue to cook until the paste is almost dry, stirring to prevent burning at the bottom of the pan.
Add the diluted tamarind water into the pan. Stir until combined. Cover with lid, and allow to come to a rolling boil.
Chop the ginger flower to bite-sized pieces. Set aside.
Cut the tomato into 6 pieces. Set aside.
Remove the heads of the okra. Set aside.
Remove the Vietnamese Coriander leaves from the stalks. Set aside.
Remove the lid from the pan. Add the ginger flower and salt.
While the gravy is in a rolling boil, carefully add the fish so that it is submerged in the gravy. Do not stir.
Add okra and tomato carefully to the top of the gravy. Cover with the lid and allow to simmer for 3-4 minutes.
Remove the lid and gently stir the fish to ensure that they are not stuck to the bottom of the pan.
Taste the gravy. Adjust taste if needed.
Add the Vietnamese Coriander. Cover with the lid and allow to cook for 1-2 minutes.
Dish onto a shallow plate and serve.