Remove the outer leaves from the cauliflower and trim the stem so the cauliflower sits flat on a cutting board. Slice the cauliflower into 1-inch thick "steaks" by cutting through the center of the cauliflower head. You should get 2-3 steaks depending on the size of the cauliflower.
Brush both sides of the cauliflower steaks with olive oil and place them on a baking sheet lined with parchment paper. Sprinkle the spice mixture over both sides of the cauliflower steaks. Roast the cauliflower steaks in the preheated oven for about 25-30 minutes, flipping halfway through, until they are tender and golden brown.
Remove the cauliflower steaks from the oven and let them rest for a few minutes before serving. Sprinkle with grated Parmesan cheese.