In a medium sized saucepot over medium heat, melt butter and sauté garlic until fragrant for 3 minutes. Add to pot cauliflower, milk, nutmeg, wine (if you choose not to use wine, substitute with another ¼ cup milk), and thyme. Bring to a gentle boil and cook for 10 minutes. Remove from heat. Using a blender, puree cauliflower with cheese until creamy and smooth.
Boil butternut squash according to package instructions. Strain and transfer to a large serving dish. Pour desired amount of cauliflower alfredo sauce over squash and gently toss. Sprinkle with extra cheese and garnish with parsley.
* Alfredo sauce makes 4 cups. Store extra sauce in an airtight jar up to 4 days in refrigerator.