Fresh mozzarella is a much more ubiquitous ingredient, but it's worth seeking out smoked mozzarella to top these simply baked mushrooms. You can find twisted, short braids of smoked mozzarella at most supermarkets.
I cut up some cold butter into tiny cubes and topped the stuffing with it, so as it heats, the butter seeps in and keeps the inside moistened. Next, I sliced some smoked mozzarella and topped the stuffed mushrooms with it. Finally, seasoned it with salt and pepper and pushed it under the broiler. In a little over 5 minutes, the cheese was bubbling, the kitchen was fragrant and the juice in the pan was totally lick-worthy!