Cut each fish into two to three pieces, depending on the size. As a practical guideline, each piece should sit comfortably in an individual soup bowl along with the broth and vegetables.
Peel the ginger and slice thinly.
Crush, peel and mince the garlic.
Peel and finely slice the onion or shallots.
Heat the cooking oil in a large pot.
Saute the ginger, garlic and onion for about 3 minutes.
Add the fish to the pot and pour enough water to cover. Season with patis.
When the water begins to boil, add the malunggay leaves, pushing them down into the liquid. Cover and simmer for 10 to 15 minutes, depending on the size of the fish, until the fish and malunggay are both cooked through.
Season with more patis, if necessary, before serving.