Cheesy Baked Cauliflower 1 head cauliflower 1 teaspoon prepared mustard 1/4 cup butter, cut into pieces 1/2 cup grated Parmesan cheese 1 teaspoon mayonnaise Steam whole head of cauliflower for 30 minutes. Drain and place on a pie plate. Preheat oven to 375 degrees. In a mixing bowl, combine mayonnaise and mustard; spread the mixture over cauliflower and dot with pats of butter. Sprinkle generously with Parmesan cheese. Bake at 375 degrees uncovered, for about 30 minutes, or until cheese is brown.