Unlike ravenbait, I'm a big fan of roasting cauliflower. My wife regularly does a recipe (think she got it from Nigella) for cauliflower roasted with chickpeas, tomatoes and spices. Delicious.
The cauliflower 'steak' is a trendy affectation, but one that I like - sear it in the pan so it's well browned on the outside, add lots of butter and other flavourings (garlic, thyme, whatever takes your fancy) and finish it in the oven. Very good indeed.
Cauliflower is also good raw. I once had cauliflower 'carpaccio' in a restaurant, which came with a vanilla-flavoured dressing. Poncey nonsense, but actually rather good.
Boiling cauliflower is just about the last thing I would do with it.