I've seen this recipe prepared in many variations from using kamias, calamansi and sinigang mix and pepper, but I still prefer the simple way my father used to cook it.
2 pompano (whole)
3 medium tomatoes (sliced thinly)
1 small onion,
1/4 cup calamansi or lime (or lemon) juice
3/4 cup water
1 tbs olive oil
Salt and black pepper to taste
2 spring onions (cut diagonally, about 1")
Clean the fish and cut two diagonal slashes on both sides. Slice tomatoes and onion into round slices thinly. Place half of the onions and tomatoes on the bottom of a deep pan. Add fish, the rest of the onion and tomatoes, lemon or lime juice, water, olive oil, spring onion, and salt and crushed pepper to taste. Let boil on medium-high heat, then cover and simmer for 10 minutes or until the fish is done.
This recipe can also be baked by following the instructions here and using a baking dish instead of a pan, cover with foil and bake for 20 minutes or until fish is done in a 375 degree F oven. Another method is to prepare it placing individual fish atop a sheet of foil. Add the ingredients over the fish. Fold the foil onto itself, crimping the edges tightly to keep the juices from dripping out. Put the packages in the baking pan and bake for about 15-20 minutes.