Whisk together the soy sauce, oyster sauce, cilantro, garlic, sugar, and black pepper in a bowl.
Skewer two pieces of pork onto two skewers so that the meat lies flat. Place the pork skewers in a large baking dish. Pour the marinade over and turn to coat the pork. Cover and refrigerate for at least one hour and up to four hours.
Heat grill to high. Remove the skewers from the marinade and grill the meat on both sides until slightly charred and cooked through, about three minutes per side. Serve with chilli Sauce on the side for dipping.
Combine all ingredients in a small bowl. Cover and let sit at room temperature for at least one hour before serving.