Marinate the pork with the onions, garlic, vinegar, soy sauce, bay leaves, and black pepper for 20 minutes.
Drain the marinade from the pork and save.
Heat up the cooking oil in a large sauté pan over medium high heat. Sauté the red bell pepper for 1 minute. Set aside in a bowl.
In the same pan, add in the pork and onions. Sauté for 5 minutes.
Pour in the saved marinade. Simmer for 5 minutes without stirring.
Pour in the water. Bring to a boil. Cover. Reduce the heat to medium low and simmer for 25 minutes.
Add in the liver. Simmer uncovered for 5 minutes.
Stir in the peas. Continue simmering for 2 minutes.
Add in the bell peppers and season with salt. Cook for 1 more minute.