01 -
Preheat the oven to 350°F (175°C). Hollow out each mushroom cap, reserving the scrapings for later use.
02 -
Heat a skillet over medium-high heat. Add the Italian sausage, diced onion, and reserved mushroom scrapings. Cook for 4 to 6 minutes, stirring until the sausage is browned and fully cooked. Drain the excess grease and return the sausage mixture to the skillet.
03 -
Stir 3 ounces of Parmesan cheese, bread crumbs, garlic, and parsley into the sausage mixture. Cook and stir for an additional 3 to 5 minutes until the mixture is heated through.
04 -
Stuff each mushroom cap with the sausage mixture and place them on a baking sheet.
05 -
Bake the stuffed mushrooms in the preheated oven for 12 minutes.
06 -
Sprinkle the remaining 1 ounce of Parmesan cheese over the stuffed mushrooms and continue baking for an additional 3 minutes, or until the cheese is melted and bubbly and the mushrooms are cooked through.
07 -
Serve hot and enjoy!.