Wash and pat dry mushrooms. Take off stems and chop into small pieces. Place mushroom caps in baking dish. Place teaspoon of sausage meat in bottom of mushroom. Press meat down into mushroom.
In a small bowl combine mushroom pieces, bread crumbs, Pecorino Romano, Parmigiano Reggiano, garlic powder, pepper, and parsley. Add olive oil until mixture is moist. If too dry add more oil.
Fill each mushroom cap generously with stuffing mixture and place in baking pan. If any stuffing is leftover, divide evenly and top each mushroom. Drizzle olive oil over each one. Pour little water in bottom of pan. Cover with foil.
Bake for 30 minutes. Remove foil, sprinkle shredded mozzarella on each mushroom and bake uncovered for another 10 minutes.
A viewer or guest of the show, who may not be a professional cook, provided this recipe. It has not been tested for home use.