Pour the water in a cooking pot. Bring to a boil.
Put-in the guava, tomato, onion, and whole peppercorn. Let it boil. Continue to boil (covered) for 15 minutes or until the guava and vegetables are soft. You may add more water if needed.
Using a fork of a potato masher, mash the guava and vegetables inside the cooking pot to extract the flavors. This is an optional step, be extra careful.
Pour-in the fish sauce. Stir.
Add the milkfish. Cook for 5 to 10 minutes in medium heat.
Add the okra and Jalapeno. Continue to cook for 5 minutes.
Put-in the spinach. Cover the cooking pot. Turn the heat off. Let the spinach stay in the pot for 5 minutes.
Transfer to a serving bowl. Serve.
Share and enjoy!