For best results, choose pork belly with a generous amount of fat between the layers of meat. The fat will melt during pan-grilling to keep the meat moist.
Mix together all the ingredients for the marinade, but using only half of the cooking oil, and pour over the pork slices. Mix the marinade into the meat well.
Cover the bowl and allow the pork belly slices to soak up the flavors for at least an hour.
Heat a skillet (cast iron is especially good) and brush the remaining cooking oil on the cooking surface.
Pan-grill the pork belly slices in batches over high heat, three to four minutes per side, until the marinade caramelizes and forms a light crust on the surface.
Serve the spicy pan-grilled pork belly over rice garnished with sliced scallions and toasted sesame seeds.