Cut the cauliflower into 2 to 3 inch pieces. Boil the cauliflower until it is fork tender, about 7-10 minutes. Drain the cauliflower.
Place the cauliflower in a strong blender or a food processor. Add the butter, olive oil, rosemary, salt and pepper, to taste to the cauliflower. Puree until the mixture is smooth and creamy.
Serve immediately.
Recipe by The Little Chef at http://littlechefblog.com/cauliflower-mashed-potatoes/