Preheat the oven to 220°C (430°F) and line a large baking sheet with parchment paper.
Quarter the cabbage, then remove the white core and discard. Finely chop the cabbage and place it into a mixing bowl.
1 small head red cabbage
Add the oil, vinegar, honey, mustard, salt, and pepper to the bowl. Use your hands to mix very well, massaging into the cabbage, until fully coated.
1 tablespoon olive oil, 1 tablespoon balsamic vinegar, 2 teaspoons honey or maple syrup, 1 teaspoon Dijon or German mustard, 1/2 teaspoon sea salt, 1/2 teaspoon black pepper
Transfer the cabbage mixture to the prepared baking sheet. Roast for about ten minutes, or until the cabbage is browned in some places and just cooked but still slightly crunchy. Serve immediately.