Heat oil in a pan.
Once the oil turns hot, fry the sliced milkfish until medium brown. Flip the fish to fry the other side.
Remove the fish from the pan. Set aside.
In another pan, use small amount of the previous oil then fry the onions for 2 minutes. Set aside.
In the same pan, cook garlic until brown. Then pour-in water, soy sauce, calamansi extract and black pepper. Let it boil for 5 minutes.
Then put-in fried bangus and simmer for another 3 minutes.
Pour the melted cornstarch and stir continuously for 2 minutes.
Serve while hot. Enjoy!