The vegetable retains some texture and has none of that sulfury taste and mushiness of cabbage that has been improperly cooked. This also makes a great breakfast when served with fried eggs on top.
Heat a 14-inch skillet over medium-high heat, and then add the oil and onion. Saute to soften the onion slightly, about 2 minutes. Stir in the tomato, ginger if using, and red-pepper flakes. Cook for an additional 2 minutes.
Add the cabbage and 1 1/2 teaspoons salt. Stir to combine. Cover, and reduce the heat to medium low. Cook, stirring occasionally as the cabbage begins to collapse. Add a little water, 2 tablespoons at a time, as needed if the cabbage becomes too dry. (This depends on the moisture level of the cabbage. You don't want it too wet.) Cook for approximately 13 minutes, or until the cabbage is just tender. Salt to taste and serve.