Preheat oven to 350°F.

Cook cauliflower until tender and drain.

In ovenproof skillet, heat butter, cheese, cream and mustard covered, stirring occasionally, about 10 min. until cheese is melted.

Add cauliflower to cheese mixture and mix well. Bake 20 min. or until lightly browned.

Alternatively, transfer mixture to 9" pie plate and bake off in oven.