In a small bowl combine the oyster sauce, salt, cornstarch, and water, stirring well to combine. Put aside until needed.
Stir Fry
Bring a small pot of water to a boil. While this is happening wash the bok choy. Dip the bok choy into the water for 30 seconds to blanch it. Note: Baby bok choy can be cooked whole, and larger bok choy can be cut into smaller pieces. If camping, this step can be skipped, however, the wok cook time will need to be a little longer.
Heat the wok to medium heat then add the oil and garlic, then stir-fry for 1 minute.
Add the bok choy to the wok and mix with the garlic. Mix in the reserved sauce. Stir fry until the sauce has heated and started to bubble; serve.