The important thing is not to overcook the vegetable. What I do at home is put the vegetable in about two inches of salted water. Bring it to a boil. Pour the water off. Add butter, cheese and milk. Cover immediately. It is important to trap the steam in- this is what cooks the cauliflower and melts the cheese. Place in the oven on warm. Check the cauliflower after 15 minutes. Stir the cheese into the milk and check the cauliflower. Continue to cook on low heat until the cauliflower is crisp tender but not mushy.