Preheat your oven to 425°F (220°C).
Remove the leaves and stem from the head of cauliflower, slice it into ¾-inch thick 'steaks.'
Mix together the olive oil, garlic powder, paprika, onion powder, salt, and black pepper. Brush this mixture on both sides of each cauliflower steak.
Place your seasoned cauliflower steaks on a parchment-lined baking sheet in a single layer.
Roast in the preheated oven for about 25-30 minutes, turning halfway through cooking time.
Remove from the oven, let cool briefly, and garnish with fresh herbs if desired. Serve warm.