Combine all ingredients in a small bowl. Cover and let sit at room temperature for at least 1 hour before serving.
For the pork:
1) Skewer 2 pieces of pork onto 2 skewers so that the meat lies flat. Place the pork skewers in a large baking dish. Whisk together the soy sauce, oyster sauce, coriander, garlic, sugar, and black pepper in a bowl. Pour the marinade over the pork and turn to coat. Cover and refrigerate for at least 1 hour and up to 4 hours.
2) Heat griddle to high. Remove the skewers from the marinade and griddle the meat on both sides until slightly charred and cooked through, about 3 minutes per side. Serve with chili sauce on the side for dipping.