Preheat oven to 425F.
Roughly chop the cauliflower into bite sized pieces.
Place the cauliflower in a bowl then pour the olive oil and ranch seasoning over the top and toss to coat.
Spread the cauliflower mixture in a single layer on a cookie sheet. Then sprinkle the parmesan over the top.
Bake for 10 minutes. If you want a little extra browning on the tips, broil for an extra 1 minute.
Serve hot. Enjoy!