Preheat the Oven - Adjust the oven rack to the lower third position. Preheat to 500ºF (260ºC).
Slice the Cauliflower - Remove the outer green leaves from the head of the cauliflower and trim the stem. Using a large knife, cut the cauliflower in half lengthwise through the center. Cut a 1 ½-inch thick steak from each half. If the head is large, carefully cut one more steak from each cut side. Repeat the process with the other head of cauliflower. Trim any florets not connected to the stem. There should be about 4 to 8 pieces in total. Place them on a rimmed baking sheet.
Prepare the Seasoning - In a small bowl mix together salt, pepper, garlic powder, and paprika.
Season the Cauliflower - Drizzle olive oil on both sides of each steak. Evenly sprinkle the seasoning mixture on both sides, about ¼ teaspoon per side.
Roast the Cauliflower - Tightly cover the baking sheet with foil and bake for 5 minutes. Remove the foil and continue roasting for 10 minutes. Carefully flip each piece and roast one more time until a golden brown crust forms, about 6 to 8 minutes.
To Serve - Transfer to a serving platter and garnish with parsley.
Recipe Yield: 2 to 4 steaks depending on how large the cauliflower head is.