Similar to a quiche but firmer and without a crust, I really liked this recipe: cauliflower and parmesan cake. It was delicious cold.

I'd imagine you can find kosher parmesan-like cheese.

A word of warning: there didn't seem to be enough batter to engulf the cauliflower the way I'd expected, either of the two/three times I've made this. But it didn't matter in the end.