Preheat the Oven: Preheat the oven to 400°F (200°C). Line a baking sheet with parchment paper or lightly grease it.
Prepare the Cauliflower: Trim the cauliflower’s stem and remove the leaves. Slice into 1-inch thick "steaks." Save any smaller pieces for roasting as well.
Make the Marinade: In a bowl, whisk together olive oil, harissa paste, honey, lemon juice, garlic powder, smoked paprika, cumin, salt, and pepper.
Coat the Cauliflower: Brush each cauliflower steak generously with the harissa honey marinade, coating both sides.
Roast the Cauliflower: Place the cauliflower steaks on the baking sheet and roast for 20-25 minutes, flipping halfway through until golden and tender.
Serve and Garnish: Once roasted, garnish with fresh parsley and serve hot. Enjoy!