We had mushrooms similar to these at a pizza place in Nevada and we loved them. So I had to try and come up with a recipe as similar as possible. And I do believe I came close if not even better. These little gems have a bite to them so if you want them more mild you may want to mix half hot sausage and have regular to tone it down. But I find this way is the best.
48 large mushrooms, stems removed (reserve), or more as needed
24 chopped mushroom stems
1 pound ground hot Italian sausage ( I use Jimmy Dean hot sausage)
1 medium onion, chopped
4 ounces grated Parmesan cheese, divided (I like Italian blend).
1/4 cup bread crumbs
1 teaspoon minced garlic
1 teaspoon chopped fresh parsley
monteray jack cheese
Preheat oven to 350º
Heat a skillet over medium-high heat. Cook and stir sausage, onion, and reserved chopped mushroom scrapings in hot skillet until sausage is browned and cooked through, 4 to 6 minutes. Drain and discard grease; return sausage mixture to skillet.
Stir 3 ounces Parmesan cheese ( or the blend), bread crumbs, garlic, and parsley into sausage mixture. Cook and stir until heated through, 3 to 5 minutes.
Fill the mushroom caps with, the stuffing mixture, brush w/melted butter and top with the monteray jack cheese or the Italian blend. Lightly sprinkle w/paprika and bake in a roasting pan or baking dish for about 12 mins or until cheese is melted. Broil for 1-2 mins to brown cheese. Sprinkle with fresh chopped parsley to garnish, if desired.