Preheat oven to 425°F / 220°C. Line a large baking sheet with parchment paper.
Prepare cauliflower: Cut it into even florets, then pat them dry with a clean towel.
Toss ingredients: In a large bowl, mix cauliflower, olive oil, garlic, salt, pepper, and paprika. Stir well to coat evenly.
Roast: Spread the florets in a single layer on the sheet pan. Roast for 15–18 minutes, until golden on the bottom.
Add Parmesan: Flip the florets, sprinkle grated Parmesan, and roast another 7–10 minutes until crisp and cheesy.
Finish: Remove from oven, sprinkle chopped parsley, and squeeze fresh lemon juice over the top.
Serve: Enjoy warm as a side dish or light lunch for 4 people.