Trim about 2 inches from the kangkong stalks and discard the excess.
Cut the kangkong into 3-inch lengths. Make sure to separate the sturdier stalks from the leaves then wash thoroughly and drain well.
Heat the oil in a wide skillet over high heat. Once the oil is heated, add the onions and garlic then cook them until they turn limp. Make sure to stir them while they're cooking so they don't stick to the skillet.
Add the pork and stir until it is cooked or until it is lightly browned.
Add vinegar and bring the mixture to a boil. Let the mixture cook for about 2 to 3 minutes then add the soy sauce and water.
Mix the ingredients until they're incorporated then bring it to a boil for about 1 to 2 minutes.
Once the mixture is boiling, lower the heat, cover the skillet, and let it simmer for about 8 to 10 minutes or until the pork is tender and the sauce is reduced. Season with pepper until you reach your desired flavoring.
Increase heat to high then add the kangkong stalks and cook, while stirring regularly, for about 1 to 2 minutes. Add kangkong leaves and cook, stirring regularly, for another minute or until just wilted and covered with sauce. Remove from heat and garnish with fried garlic bits, if desired. Serve hot.
After cooking the stalks, add the kangkong leaves and cook, stirring regularly, for another minute or until the leaves are just wilted then covered with sauce.
Remove the skillet from the heat and transfer the mixture to a plate. Garnish with fried garlic bits if you want then serve fresh.