Heat the cooking oil in a large pot over medium heat. Sauté the julienned ginger, sliced onion, and tomatoes until they’re soft and aromatic, about 3-4 minutes.
Add the quartered gabi to the pot and pour in the water. Bring the mixture to a boil, then reduce the heat to a simmer. Cook for about 10 minutes or until the gabi starts to soften.
Add the okra, snake beans, labanos, and green chilies to the pot. Continue simmering for another 5-7 minutes until the vegetables start to soften but still have a slight crunch.
Stir in the sinigang mix powder and fish sauce. Adjust the seasoning based on your taste preference, adding more sinigang mix or fish sauce if needed.
Gently place the tilapia into the pot. Cover and cook for 10-12 minutes, or until the fish is fully cooked and flakes easily with a fork.
Add the kangkong leaves and cook for 1-2 more minutes until they are wilted but still vibrant green.
Serve the Sinigang na Tilapia hot, with steamed rice. Enjoy!