Remove scales, gills and innards by cutting the under belly up to the head of each biya. Wash fish thoroughly drain.
In a clay pot (preferably and or vinegar non reacting pot) add in garlic, onion, peppercorns and ginger (also the tomatoes, if desired) at the bottom. Arrange biya side by side, add in the vinegar and about 1/2 cup of water.
Season with salt to taste and drizzle with cooking oil.
Add the long green chili on top and sliced eggplants or talong.
Cover and simmer in medium heat for 10 to 15 minutes or until fish are cooked and most of the liquid has evaporated.