Bring chicken stock to a boil in a large pot.
Smash the sliced ginger with the side of a knife to bring out the flavor and add to the pot with the garlic, cover and cook 5 minutes.
Add the baby bok choy and partially cook 5 minutes.
Add the frozen wontons and mushrooms, simmer for 5 more minutes, until the wontons are heated through and bok choy is tender and wilted.
Stir in soy sauce, sesame oil, and oyster sauce.
Garnish with scallions!