In a bowl combine the parmesan, paprika, onion powder, and garlic powder.
Slice the cauliflower into even-sized florets approximately 1cm thick (It doesn't have to be absolutely perfect).
Toss the cauliflower in the oil and flavourings. Spread the oiled florets out on a baking tray.
Bake in a moderate oven 160 degrees Celsius (320 F) for 30 mins (the cauliflower should be tender at this point. If you like your roast cauliflower crispy then up the oven temperature to 200 degrees celsius and bake for another 5 minutes.
Taste the roast cauliflower, season with salt and pepper if desired.
Notes
If you want the cauliflower to be even more flavourful sprinkle a little extra parmesan on top of the cooked cauliflower before serving.
Try not to be tempted to roast the cauliflower hot and fast, it does much better in a moderate oven for a little longer.