1. Cauliflower puree: Bring a large pot of salted water to a boil. Add cauliflower; cook for 15 minutes or until very tender. Drain, pressing lightly to release liquid.
2. Add cooked cauliflower into the bowl of a food processor and puree. Add salt, nutmeg, cayenne, butter, and Parmesan and puree again. Add milk as needed for a creamy texture. Spoon into a bowl; stir in parsley. Keep warm.
3. Beef: Heat oil in a large nonstick skillet over medium-high heat. Season sirloin with salt, pepper and 1/8 tsp of the dried thyme. Cook for 4 minutes, turn and cook for an additional 3 minutes. Remove from skillet.
4. Reduce heat to medium and add port to skillet. Cook 30 seconds, scraping up browned bits from pan. Add broth, ketchup and the remaining 1/8 tsp thyme. Cook 2 minutes, stirring often.
5. Slice steak thinly against the grain. Spoon some of the sauce over the sliced steak and serve with the cauliflower. Also, serve with steamed garlicky green beans, if desired.