Sprinkle salt and pepper on bangus belly then dredge bangus belly in flour. Fry bangus belly until golden brown. In a separate pan, saute' garlic. Then, add soysauce, oyster sauce, calamansi juice and water. Add brown sugar followed by the bangus belly. Let it simmer for 2-3 minutes. Then, add white onion and green onion.
Cut the bangus into you desired size then separate. Cut all the calamansi in half and squeeze the juice out of it, use a strainer to separate the seed then throw it away. In a large bowl add half of the calamansi juice and half of the soy sauce then the black pepper.
In a pan, saute the garlic in oil, then add the onions. In another pan, fry the boneless bangus. Take off from the pan when done and place on your serving plate.