I wouldn't use gravy if you want it chinese style.
It will probably be a mixture of soy sauce, oyster sauce and a thickening agent like cornstarch. Then black pepper, you probably wont need any additional salt, as soy sauce is quite salty. I tend to use a mixture of both light and dark soy sauce.
The chinese tend to coat their meat in the cornstarch, rather than adding it to the sauce, then fry the meat in a wok, add the sauce and it will then automatically thicken.