Prepare the fish by washing and removing any unwanted parts.
Grate some kunyit to add color and flavor. Alternatively, you can use garam if desired, but it's optional.
Cut 2 serai in half and slice 1 bulb of bawang merah.
Chop 6 cloves of bawang ros and mince 6 cloves of bawang putih.
Add a small spoonful of sawi kacau to the cooking base for some green color and flavor.
Grind or add halia (turmeric) to taste, then add it into the pelantin (cooking liquid).
Add 5-6 pieces of cili padi that have been cut in half. Then, pour in water, adjusting the amount as needed for your pot.
Stir in 2 tablespoons of vinegar for sourness and sweetness, followed by 1 tablespoon of sugar and a pinch of salt (if preferred). This forms the base seasoning.
Add sliced tomatoes to the mixture and let them cook until they start to soften. Then add the prepared fish. Cook over low heat until the fish is cooked through and has absorbed the flavors. Enjoy!