Start by preparing the red cabbage. Remove any damaged outer leaves and then cut the cabbage into ½ inch slices.
In a small bowl, whisk together the olive oil, Dijon mustard, minced garlic, onion powder, salt, and pepper.
Place the red cabbage wedges on a large baking sheet lined with parchment paper or a silicone baking mat.
Brush the cabbage wedges generously with the mustard glaze, making sure to coat them evenly on both sides.
Roast the cabbage in the preheated oven for about 20-25 minutes or until the edges are crispy, and the cabbage is tender. You may want to flip the slices halfway through the roasting time for even cooking.
Once the roasted red cabbage is done, remove it from the oven and transfer it to a serving platter.
If desired, sprinkle fresh parsley over the top for added flavor and presentation.
Serve the roasted red cabbage immediately as a side dish to your favorite low-carb main course.
Notes
The cabbage is best served warm. Leftovers can be stored in an airtight container in the refrigerator up to 2 days. They are best eaten cold.