Cavolfiori al gratin

I have access to the camera again!! So I decided I'd take a picture of one of the first dishes I cooked in the new kitchen, just to start: 'cavolfiori al gratin', or 'gratin cauliflower'. Being in Berkeley, I'm turning more and more into a vegetarian. Not sure if it's because of the Yoga classes or because veggies look so good here, or because I've been reading some about how less sustainable it is to be a meat eater than vegetarian.. anyway, no worries for whoever invites me for dinner, so far: I'm not strict on it at all, I'm just decreasing the (already small) amounts of meat I tend to eat.
Anyway, the first weekend I arrived, Lucas brought me to the Berkeley Bowl, a grocery store well-known for the humongous section of vegetables and fruit. They have both really exotic and more common things, but even in the more common section, there are so many choices.. anyway, I saw this cauliflower there and I thought I may make something good out of it.

Cavolfiori al gratin / gratin cauliflower
Boil the cauliflower cut into pieces for ~10 min, in water with salt. I read somewhere that if you add a piece of bread soaked in vinegar, you won't have the typical smell of boiled cauliflower spreading everywhere in your home. I was pretty skeptical, but I tried, and I must say that it seems to work! If you do try, let me know if I was just deluding myself or not. :)
While it cooks, prepare besciamella sauce (see here, or anyway, dissolve ~2 tbsp flour in ~2 cups of milk, heat, add salt, 1 tsp nutmeg and 1 tbsp butter, bring to boil and let it thicken, adjusting with the amount of milk/time of heating in order to get to a dense consistency). Once the cauliflower is done, take it out, place the pieces in a baking pan, cover with besciamella, add small pieces of a cheese that can melt (I had some fresh provolone), and pieces of nuts. Broil for a few minutes until golden on the top. I served it with steamed whole grain rice.