Take 250 grams pak choi. Trim off woody ends (if necessary), then cut in half.
Carefully rinse the pak choi under water. Be sure to wash in between the stems as best you can to remove any lingering grit. Once clean, pat dry.
Add around 1 inch of water to a large steamer pot. Cover and set your stove to medium heat. Bring the water to a boil.
Next, add the halved pak choi to a steamer basket. Arrange the pak choi with the stems facing downwards, as these will take longer to cook.
Place the steamer basket with the pak choi in the pot. Cover the steamer pot with a lid and let the pak choi cook for 5 minutes.
If you're using baby pak choi, reduce the cooking time to 3 minutes.
Optionally, to make the sesame garlic oyster sauce, heat 1 teaspoon toasted sesame oil in a small saucepan. Add 5 cloves garlic (sliced), and sauté for a few seconds.
Next, add 1 tablespoon vegetarian oyster sauce, 1 teaspoon light soy sauce, 1 teaspoon sugar, and 1 tablespoon water. Mix and cook for an additional 30 to 60 seconds, or until thickened.
Remove the pak choi from the steamer basket. Arrange on a serving dish and pour the sauce on top.
Notes
To make this recipe gluten-free, substitute light soy sauce for tamari, 1:1.