01 -
Heat the oven to 425°F (220°C). Line a large baking sheet with parchment, or use two sheets if needed so the cauliflower is not crowded.
02 -
Trim away the leaves but keep the core intact. Cut each cauliflower head from top to stem into 3/4-inch to 1-inch steaks. Save any loose florets for the same pan.
03 -
Stir the olive oil, garlic powder, onion powder, smoked paprika, salt, and pepper in a small bowl until evenly combined.
04 -
Arrange the cauliflower on the baking sheet. Brush both sides with the seasoned oil. Roast for 18 minutes, until the underside is golden.
05 -
Carefully flip each steak with a wide spatula. Roast for 8-10 minutes more, until the stem is almost tender when pierced with a knife.
06 -
Sprinkle Parmesan, mozzarella, and cheddar over the steaks. Return to the oven for 6-8 minutes, until the cheese is melted, bubbling, and lightly browned.
07 -
Let the steaks rest on the pan for 2 minutes so the cheese settles. Sprinkle with parsley and serve hot.