Prepare the fish: Rub salt all over the bangus slices. Let it sit for 10 minutes. This helps remove excess moisture and enhances the flavor.
Fry the fish: Heat oil in a pot over medium heat. Fry each side of the fish for 1-2 minutes until lightly browned. Remove the fish from the pot and set aside.
Sauté aromatics: Using the remaining oil in the pot, add onion, half of the tomatoes, and miso paste. Sauté for 2 minutes to blend flavors and soften the vegetables.
Create the broth: Return the fried fish to the pot and pour in water. Bring to a boil.
Simmer: Cover and cook using low to medium heat for 10 minutes.
Add souring agent: Stir in the tamarind soup base mix. Cook for 2 minutes.
Cook vegetables: Add green peppers, string beans, and okra. Stir, cover, and cook for 5-7 minutes.
Season: Add fish sauce and ground black pepper to taste. Stir well to combine.
Finish with greens: Add the kangkong leaves to the pot. Cover and turn off the heat. Let it steep for 5 minutes to wilt the greens perfectly.
Serve: Transfer to a serving bowl and enjoy hot with steamed rice!