Preheat your oven to 220°C (430°F) and line a baking sheet with parchment paper.
Trim the cauliflower by removing the leaves and core, then place it upside down and slice into approximately 1.5-inch thick steaks, aiming for two to three steaks from the head.
Use a pastry brush to evenly coat both sides of each cauliflower steak with olive oil, ensuring a glossy surface that promotes crisping.
Sprinkle the steaks generously with salt, pepper, and smoked paprika, pressing lightly to help the spices adhere.
Arrange the seasoned steaks flat on the prepared baking sheet, leaving space between them for even roasting.
Roast in the oven for 15 minutes until the edges start to turn golden and crispy.
Use tongs to carefully flip each steak over, then return to the oven and roast for another 10-15 minutes until deeply caramelized and crispy at the edges.
Check the doneness by inserting a knife; the center should be tender but the edges crispy and deep amber in color.
Remove from the oven, squeeze fresh lemon juice over the steaks, and sprinkle with chopped parsley for a bright, fresh finish.
Serve immediately while hot and crispy, enjoying the smoky aroma and satisfying texture.