If any cauliflower florets are larger than 2 inches, cut into smaller pieces
Toss florets with olive oil on foil-lined baking sheet until well-coated, then spread out florets in single layer
Bake at 400° F until tender, 15 to 20 minutes
While baking, proceed to next step to prepare sauce
Make Sauce: Whisk all sauce ingredients together in small saucepan over medium heat until melted and smooth, about 5 minutes, reducing heat as needed so that sauce isn't hot enough to simmer
Once combined, keep warm over low heat while waiting for cauliflower to bake
Serve: Toss roasted cauliflower with sauce in mixing bowl until well-coated
Serve and evenly sprinkle parmesan cheese and black pepper on top