Place the entire slab of pork belly skin side up in a large pot. You can cut it to fit in the pot, but not too small so it won't dry out.
Add garlic, bay leaves, 1 tablespoon kosher salt (use less for table salt), and some ground black pepper or peppercorns. Completely submerge the meat in water.
Bring it to a boil over medium-high heat, then lower the heat and simmer until fork tender. Depending on the thickness, it may take 1½ to 2 hours on the stove or 30 to 45 minutes in a pressure cooker. If your pork belly comes with some bones, remove them before frying for easier cutting.PRO TIP: For crispy, crunchy skin that won't break your teeth, it's crucial to boil the meat until the skin becomes very tender and almost gelatinous. When you've achieved that, you are halfway there.
Transfer to a plate with the skin side up, then salt the skin to help draw out the moisture. Let it dry uncovered overnight in the fridge.If you need it sooner, place it in the oven at 250° F (121° C) for about an hour to dry the skin. You can also freeze them and fry them later.
Slice into 3-inch thick pieces to get plenty of crispy exterior while the inside stays juicy. As an option, you can score the skin to expose more fat for crispier skin.
Sprinkle salt all over the meat, except for the skin, which has already been salted.
Place the pork belly in the air fryer basket with the skin side up. Do not overcrowd, leaving enough space between them to allow air to circulate and promote even cooking.
Air-fry it at 400° F (204° C)for 20-30 minutes, depending on the size or thickness. Check it periodically to ensure that it turns golden brown and the skin becomes crispy.
Let it cool for 5-10 minutes, then cut it into bite-size pieces.
Notes
Pork belly: A boneless cut, sometimes with ribs attached, with thick layers of fat and meat. Choose skin-on pork belly with enough fat for the best flavor and texture. Pork shoulder, a cheaper and leaner cut with slightly tougher meat, is the closest substitute.
Dipping sauce: Serve with lechon sauce, a thick sauce that is sweet and tangy made with pork liver. You can also use Mang Tomas all-purpose sauce or a spicy vinegar dipping sauce.