1 kgm. Bangus (boneless and sliced into 4)
1/4 cup soy sauce.
6 pcs. calamansi (or more).
3 cloves garlic (crushed).
2 pcs. red onions ( 1 sliced and 1 rings). 
cooking oil ( just enough for deep frying).
salt and pepper to taste.
(OPTIONAL) mix half cup of water and 2 tbsp. of flour or cornstarch for thickening the sauce. 



Procedure:

1. In a large container, marinade boneless bangus in soy sauce, calamansi and ground black pepper for at least 1 hour. Put it in a fridge.

2. Heat the cooking oil in a pan and deep fry the boneless bangus until golden brown. Set aside. (Keep the marinade for sauce).

3. Remove the oil then stir fry crushed garlic and the sliced red onions.

4. Pour the marinade and bring to a boil. Season with salt and pepper.

5. Lower the fire and slowly add the thickening mixture. Stirring continuously until you get your desired thickness. Now add the onion (rings) and simmer for a minute.

6. In a large plate, arrange the fried boneless bangus and pour over the bistek sauce.

7. Serve hot. Share and enjoy!