Tear the pork into small pieces.
Rinse the potatoes well and cut into half-inch cubes.
Peel and finely slice the onion.
Peel and mince (or you may chop) the garlic.
Heat the cooking oil in a frying pan or wok.
Spread the potato cubes in the hot oil and cook over high heat without disturbing for a few minutes, or until the undersides are browned. Stir and continue cooking until browned all over and cooked through.
Scoop out the fried potato cubes and move to a plate.
In the remaining oil in the pan, cook the onion slices over medium heat until lightly browned and softened.
Scoop out the onion slices and move to the plate beside the potato cubes.
Spread the pork meat on the bottom of the pan.
Sprinkle in garlic and pepper. Throw in the bay leaf.
Pour in the vinegar and soy sauce.
Cook the pork over high heat, stirring often, until the meat has soaked up the vinegar and soy sauce. Taste and adjust the seasonings. If you need to pour in more vinegar or soy sauce, or both, cook longer to allow the meat to soak up the liquids.
Lower the heat to medium and continue cooking pork in the rendered fat until the meat is browned and lightly caramelized.
Add the potatoes and onion slices to the pork. Stir to distribute evenly.
Serve the pork adobo hash with rice and egg.