In a large pan over medium heat, sauté the garlic, onion, and langka in oil for a few minutes, until the langka begins to soften.
Add bay leaves and season with salt and pepper. Cook for about 10 minutes. Add vinegar and bring to a boil. Simmer until the acidic smell disappears. Add the water or vegetable/pork broth, soy sauce, and brown sugar.
Stir and simmer until most of the liquid has reduced by half.