To make the stir-fry sauce, combine the ingredients in a small bowl and set aside.
Heat a dry large wok or frying pan over medium heat.
Add the bacon and stir-fry for 3-4 minutes, or until crisp.
Add the garlic to the pan and stir-fry for 1 minute, or until fragrant.
Add the cabbage and prepared stir-fry sauce.
Increase the heat to high and stir-fry for 3 minutes, or until the cabbage has softened.
Add a pinch of pepper, to taste.
Divide steamed rice between bowls and top with the stir-fried Chinese cabbage and bacon.
Sprinkle with the spring onion and serve the black vinegar (if using) on the side.
