Heat a pan and cooking pot then pour-in vinegar and water.
Add salt and whole peppercorn then stir. Bring to a boil.
Arrange the fish in the pan along with the ginger, garlic, onion, bitter gourd, and finger chili. Cover and simmer in low to medium heat for 12 to 15 minutes.
Turn off the heat and transfer to a serving plate.
Serve hot with steamed rice. Share and enjoy!
Note: You may substitute salt with 3/4 to 1 tablespoon fish sauce.