Start by slicing the cabbage thinly and chopping the other vegetables. Thin slices cook faster and stay crunchy. Prepping everything ahead helps the stir fry cook quickly.
In a small bowl, combine soy sauce, oyster sauce, rice vinegar, sesame oil, sugar, and water. Stir until sugar dissolves. This sauce brings the dish together with a balanced sweet-savory flavor.
Heat oil in a wok over medium-high heat and add garlic and ginger. Cook for 30 seconds until fragrant. This step releases the flavors and sets the base for the stir fry.
Add carrots, bell pepper, and cabbage to the wok. Stir fry for a few minutes until the cabbage starts to soften but still has crunch. Add a splash of water or broth to help steam the cabbage.
Pour the sauce over the vegetables and toss well. Add the cornstarch mixture and stir until the sauce thickens slightly. This creates a glossy coating that sticks to the cabbage.
Turn off the heat and add chopped green onions and sesame seeds. Give it a final toss and serve immediately. The freshness of green onions makes the dish bright and flavorful.