Pat the pork belly dry. Using a sharp knife, cut it into strips about 1 1/2 inches wide, then into 1-inch pieces, keeping the skin attached. Rub with the salt, garlic and half the lime juice and refrigerate uncovered for 1 hour, or overnight, so the skin dries out.
Wipe off the garlic and pat the pieces very dry. Place them skin-side up in a large heavy pot or Dutch oven in a single layer, and add enough water to just cover the bottom of the pot.
Cook over medium-low heat. The water will evaporate and the fat will slowly render. Keep cooking, stirring occasionally, for 60 to 70 minutes, until the meat is golden and there is plenty of melted fat in the pot.
Raise the heat to high. Fry the pieces in the hot fat, turning carefully, for 3 to 6 minutes until the skin puffs and bubbles into crisp crackling. Stand back, as the skin can pop.
Lift out with a slotted spoon, drain on paper towels and sprinkle with a little salt. Serve hot with lime wedges.