Heat the oil in a large skillet or wok over medium high heat. Season the pork with salt and pepper, and sauté the pork in two batches, for 3 minutes each, until browned and almost cooked through. Transfer the pork to a plate as each batch is finished.
Return the pan to the heat, and add the remaining tablespoon oil. Add the bok choy and sauté for 2 minutes until it begins to wilt. Add the soy sauce, chili garlic sauce, scallions and 1/2 cup water to the pan, and continue to cook for 1 more minute, stirring frequently, until the sauce has blended nicely and coats the bok choy. Return the pork to the pan and cook until the pork is cooked through, about 1 more minute, and everything is well combined.