Blend all spice paste ingredients with 2 tablespoons water until smooth.
Place asam jawa in a small metal strainer over a bowl. Pour 1 cup (240ml) hot water over asam jawa. Stir and press down asam jawa with a spoon to dissolve.
Pour spice paste into a medium clay pot or non reactive pot. Pour strained tamarind juice into the pot. Stir to combine. Add crushed lemongrass, daun kesum, salt to taste, and pineapple. Again stir to combine. Place lid on the pot and allow sauce to come to a boil. Reduce heat and continue to simmer for 10 minutes.
Remove the lid. Do a taste test. Add a little sugar to taste.
Add okra and fish. Place the lid back onto the pot. Continue to cook for another 3 to 5 minutes or until okra is tender.
Turn off stove and serve warm with steamed rice.
**You can also use 2 tsp tamarind concentrate mix with 1 cup (240ml) water.