We had a cheesesteak pizza with a white sauce that was the bomb. People who tried it raved. Just almost like jackaloo’s above. I made a homemade parmesan cream sauce (heavy cream, butter, pinch of minced garlic, salt, reduced to thicken then parm and white pepper) for base, then the mozz/prov, sliced steak, red onion rings, bell pepper rings, and top with light sprinkle of sharp cheddar and very light mozz/prov. The scratch sauce makes a world of difference in richness.
Used the same sauce for a steak and potato pizza I lifted from someone’s menu.