In one bowl, combine pork and ½ cup of the vinegar, 1 teaspoon salt, and ¼ teaspoon pepper. Marinate for about 30 minutes.
In another bowl, combine the liver, heart, the remaining ½ cup of the vinegar, 1 teaspoon salt, and ¼ teaspoon pepper. Marinate for about 30 minutes.
After marinating, drain pork from marinade and squeeze excess liquid. Reserve marinade.
Drain liver and heart from marinade and squeeze excess liquid. Reserve marinade.
In a pan over medium heat, heat oil. Add onions and garlic and cook until softened.
Add minced lung and cook, stirring occasionally, until browned and sizzling.
Add pork and cook until lightly browned.
Add fish sauce and cook, stirring occasionally, for about 2 to 3 minutes.
Add reserved vinegar marinade and bring to a boil, uncovered and without stirring, for about 3 to 5 minutes. Lower heat, cover and cook until pork is tender.
Add liver and heart and continue to cook for about 3 to 5 minutes or until cooked through and sauce is reduced.
Season with salt and pepper if needed. Serve hot.