Preheat the oven to 400 degrees F (200 degrees C).
Place cauliflower florets into a baking dish. Add garlic, squeeze lemon juice over, and drizzle each piece with olive oil. Season with salt and pepper.
Bake, uncovered, in the preheated oven until the top is lightly browned, 15 to 25 minutes. Remove from the oven and sprinkle generously with Parmesan cheese.