Roasted cauliflower is yummy anyway, but when you toss it with paprika first, it comes out a brilliant red color. I do make sure that there are other things going in the oven though, so as not to waste oven heat.
Cut apart one head of fresh cauliflower into similar-sized florets. Place in a bowl and sprinkle with a bit of olive oil, salt, and pepper. Next, sprinkle with a generous amount of Hungarian-style paprika and toss everything to evenly coat. There should be enough paprika that the cauliflower is more red than white. If you just want plain roasted cauliflower, then leave out the paprika.
Roast on a baking sheet in a hot oven for 20 -30 minutes or until the cauliflower can be pierced with a fork and has browned slightly. This a nice change from steamed cauliflower, as it retains a bit more of its crisp texture when roasted.
As a final note, I have never gotten this to work with frozen cauliflower, so please let me know how if you can get it to turn out with the frozen stuff.