In a small bowl, place broth, oyster sauce, shoyu, sugar, sesame oil, and cooking wine; stir to combine; set aside.
In a wok or large skillet, heat oil over high heat. Add garlic and ginger and stir-fry until fragrant, about 30 seconds. Add mushrooms and stir-fry for 1 minute. Add salt to taste. Add chicken broth mixture and bring to a boil.
Reduce heat to medium-low. Cover and simmer, flipping mushrooms every 15 minutes, until mushrooms are tender, 30 to 45 minutes total.
Place bok choy on a round serving plate, arranging in a single layer with leaves pointed toward center; set aside.
When mushrooms are ready, add cornstarch slurry to mushrooms and cook uncovered until sauce is thickened, 1 to 2 minutes. Arrange mushrooms over the bok choy and pour sauce over mushrooms.
Serves 6.
Approximate Nutrient Analysis per serving (not including salt to taste or optional ingredients):
100 calories, 6 g fat, 1 g saturated fat, 0 mg cholesterol, 500 mg sodium, 12 g carbohydrate, 2 g fiber, 2 g sugar, 3 g protein
