Rinse fish and drain well. Season with salt and pepper to taste.
In a skillet over medium heat, heat about 2 inch deep of oil.
Carefully add fish in the hot oil and cook for about 3 to 5 minutes on each side or until lightly browned. Remove from pan and drain on paper towels.
In another pan over medium heat, heat about 1 tablespoon of oil. Add onions, garlic, and ginger and cook until softened.
Add tomatoes and cook, mashing with the back of the spoon, until softened and release juices.
In a bowl, mash tahure. Add vinegar and water and stir until combined.
Add tahure mixture to the pan and boil, uncovered and without stirring, for about 2 to 3 minutes.
Add tausi and stir to combine.
Add bangus in a single layer.
Cover, lower heat, and continue to cook for about 4 to 6 minutes or until fish.
Season with salt and pepper to taste. Serve hot.