Preheat oven to 425F. Cut cauliflower into florets and put on a lightly greased baking sheet. Toss in the garlic. Sprinkle lemon juice over cauliflower and drizzle each piece with olive oil. Sprinkle with salt and pepper. If the oven hasn't reached 400 F. yet, set aside until it has.
Place pan in the center of hot oven, uncovered, for 30-35 minutes, or until the top is lightly brown. Test with a fork for desired doneness. Fork tines should be able to easily pierce the cauliflower. Remove from oven and sprinkle generously with Parmesan cheese. Serve imediately.