Partially cooking the cauliflower in the microwave and then soaking up some of the moisture should produce a creamy and tender casserole. Skipping this step may lead to a soggy or watery dish, which certainly isn’t the goal. You can also brown the cauliflower in a pan on the stovetop. Like with the microwave method, be sure not to overcook the cauliflower. You want it to be tender enough to pierce easily with a fork. If you partially cook the cauliflower on the stove, you won’t need to steam or remove the moisture. Instead, browning the cauliflower will handle both the water removal and the cooking.