Combine the soy sauce, sesame oil, oyster sauce, brown sugar, onion powder, garlic, black pepper and chili garlic sauce into a Ziploc bag with the pork tenderloin and allow to marinate. Pour the marinade and pork into a dish to cook at 400 degrees for 30- 45 minutes (depending on the size of the pork, read your label!).
Remove the pork and add the marinade to a saucepan. Combine the broth with the cornstarch and add it to the marinade. Heat until thickened and combined. Pour over pork and enjoy!