In a pot over medium, place water, fish sauce, salt, peppercorns, bay leaves, and pork skin. Boil for about 30 minutes.
Remove meat and scrape off excess fat from the skin. Pat dry skin.
Form a mold with foil and wrap the skin around the foil, tie with strings. Ends may be secured with additional pork skins.
Sundry for a day (or bake in the lowest heat setting for 6 hours).
In a pan over medium heat, fry fat from the pork skin in oil. Sauté garlic, onion, and siling labuyo for a few minutes.
Add chopped pork meat and saute.
Add tomato and mix. Mix in bagoong and continue cooking for a few minutes.
Add rice and cook until dried up. Spread mixture onto a plate. Set aside to cool.
Place a moderate amount of cooled bagoong rice in the middle of the pork skin. Wrap the skin around the mixture and tie it tightly into a log form, making sure there are no openings.
Fry in oil over medium heat until skin puffs up into chicharron. Roll occasionally to evenly cook the skin. Drain over a paper towel.