Preheat the oven to 400°F (200°C). Prepare a baking sheet with parchment paper or grease lightly with olive oil.

Remove outer leaves from the cabbage and slice into ¾-inch thick 'steaks,' keeping the core intact.

In a bowl, mix olive oil, garlic powder, smoked paprika, onion powder, thyme, salt, and black pepper until well-blended.

Generously coat both sides of each cabbage steak with the seasoning mixture.

Arrange the seasoned cabbage steaks on the baking sheet in a single layer, leaving space between them.

Roast in the oven for 25 to 30 minutes, flipping halfway for even cooking.

Once done, let cool slightly on the baking sheet. Optionally top with Parmesan cheese, red pepper flakes, or parsley before serving.