Preheat your oven to 400°F (200°C). If grilling, preheat the grill to medium heat.
Rinse the cabbage under cool water and remove any damaged outer leaves.
Place the cabbage on a cutting board and carefully slice it into 1-inch thick steaks.
Arrange the cabbage steaks on a baking sheet lined with parchment paper for easy cleanup.
In a small bowl, mix together the olive oil, garlic powder, paprika, salt, and black pepper.
Brush or spoon the oil mixture generously over each cabbage steak, ensuring they are well-coated.
If using parmesan cheese, sprinkle it over the cabbage steaks at this point.
Roast the cabbage in the oven for 20-25 minutes or grill for about 8-10 minutes on each side, until they are tender and starting to caramelize.
Once cooked, remove the cabbage steaks from the oven or grill and let them cool for a couple of minutes.
Serve warm, garnished with fresh parsley if desired.