If you use green cabbage here, add it a few minutes before the scallions.

2 T peanut oil, or other vegetable oil
6 c thinly sliced Napa or green cabbage
4 – 5 scallions, chopped
1/2 c vegetable or chicken broth, or water
1 T soy sauce
2 T rice vinegar or white wine vinegar
1 t sugar
1/2 t red pepper flakes

1. Heat oil in a skillet over high heat. Add Napa cabbage and green onions and stir-fry until vegetables begin to brown a bit, 2 or 3 minutes. Add broth, soy sauce, vinegar, sugar, and red pepper flakes. Bring to the boil, reduce heat to medium, cover, and cook until vegetables are slightly softened but still crisp, 3 – 4 minutes more. Serve.