In a pan over medium heat, heat oil. Add tilapia and fry, turning once or twice, until golden and cooked through. Remove from pan and drain on paper towels.
In a pot over medium heat, bring enough water to cover to a boil. Add labong and cook for about 20 to 25 minutes. Drain well and discard the liquid.
In another pot over medium heat, combine 5 cups of water and onion. Bring to a boil.
In a bowl, combine bagoong with ½ cup of the boiling water. In a fine mesh strainer, strain bagoong to extract juice and discard small fish particles from the bagoong.
Add the bagoong sauce into the pot. Lower heat to simmer.
Add the labong and continue to cook for about 7 to 10 minutes or until tender.
Add fried fish and cook for another 3 to 5 minutes to slightly soften and infuse flavor.
Add saluyot leaves and continue to cook for about 2 to 4 minutes or until just wilted.
Season with pepper to taste. Serve hot.
Notes
Cook the jute leaves just until wilted as overcooking can make them bitter-tasting.