Remove the skin from the pork belly and slice it thinly (you can keep the skin if you like). Smash the garlic, and cut the cilantro and green onions into long sections.
Heat the cooking oil in a pan over high heat, add the pork belly, and stir-fry until the fat is rendered out, about 3 minutes (cook longer if you don't like fatty meat).
Add the salt and garlic, and stir-fry until fragrant.
Add the dark soy sauce, light soy sauce, and green onions, and stir-fry until evenly mixed.
Finally, add the cilantro and stir-fry for 10-20 seconds.
Video
Notes
If you usually enjoy fatty meat, you can cut the pork belly into thicker slices to retain more fat. If you don’t like fatty meat, slice the pork belly thinner and cook it longer to render out the fat.