Bring a pot of water to a rolling boil. Add the pork belly and cook for 10 minutes, or until fully cooked through. Remove the pork belly, set it aside, and let it cool.
Slice the pork belly into thin pieces and set them aside.
Heat the oil in a wok or skillet over medium-high heat. Add the pork belly and cook until the surface turns slightly brown.
Discard any excess fat from the wok or skillet. Push the pork to one side and then, add the garlic, stirring to combine well with the pork belly.
Add the green and red bell peppers, leeks, and stir for a few seconds. Then add the spicy doubanjiang, soy sauce, and cooking wine.
Stir to combine the ingredients well, then dish out and serve immediately with steamed rice.