either way, all i did was boil a whole cauli broken up into florets until soft, drain it well, then whizz it in a food processor with the grated cheeses (a couple of handfuls), a little knob of butter and a teaspoon or so or creme fraiche. i was tempted to put it some milk but think it ought to be hot and i couldn't be bothered to get a pan dirty for it. that was it. you do need to season it well - a generous amount of salt and pepper makes all the difference.
we had it with veal saltimbocca (sage and parma ham attached to the veal with a toothpick - i find the process worrying satisfying) and some swiss chard fried in the same pan while the veal was resting. it was absolutely delicious and took no more than fifteen minutes to do the whole thing. you can't argue with that.