In a large pot, add the stock, salt, onion, garlic, peppercorns, bay leaves, and oregano. Bring to a boil and add in the pork belly. Cover and let simmer for 1 hour.
Remove the pork belly to a paper towel lined tray and pat dry. You want these to be as dry as possible so they get nice and crispy.
Heat about 4 inches of oil in a large pot to 300˚F and fry the pork, in batches to prevent overcrowding, for 10 minutes, flipping halfway through.
Remove the pork from the pot and increase the heat to 400˚F. Add back in the pork and fry an additional 5 minutes, or until crispy.
Remove to a wire rack and season lightly with salt.
Chop the chicharrónes in bite size chunks and serve over warmed tortillas. Top with guacamole and a squeeze of lime.
