Cut slits on the side of the fish then season with salt. Place flour on a plate then dredge fishes until coated.
In a pan, heat oil over high heat. Fry the fishes until cook through. Transfer in a plate with kitchen towel then set aside.
Using the same pot with oil turn down heat to medium, fry sliced eggplant until wilted or approximately 2 - 3 minutes. Set aside.
Drain and rinse tausi then transfer in a bowl with 1 tsp vinegar. Stir to mix and set aside.
In the same pot, add more cooking oil if needed. Sauté onion and garlic until onions are translucent. Add tomato slices and cook until wilted for 2 - 3 minutes.
Add tausi and vinegar mixture and lightly press black bean with ladle to release flavor. Simmer for 1 - 2 minutes then add fish sauce and water then stir to incorporate.
Simmer for additional 2 minutes or until black beans are soft. Taste and adjust seasoning then add fried fish then coat with sauce. Simmer for additional 3 minutes.
Remove from heat and transfer in a serving dish. Serve and enjoy. Bon appetit!