Delicious! Made these for Christmas Eve 2016 and we all agreed. I loved using the chicken sausage instead of regular pork sausage, especially when there were plenty of other heavier meats for the dinner. And even if there weren't, I wouldn't change a thing. These are definitely going in my appetizer rotation.
24 ounces white button mushrooms
Wipe off mushrooms with damp cloth. Pop out stems, reserving both parts. Chop mushroom stems finely and set aside.
Brown and crumble sausage. Set aside on a plate to cool.
Add onions and garlic to the same skillet; cook for a few minutes over medium heat. Pour in wine to deglaze pan, allow liquid to evaporate. Add in chopped mushroom stems, stir to cook for 2 minutes. Add salt and pepper to taste. Set mixture aside on a plate to cool.
In a bowl, combine cream cheese and egg yolk. Stir together with parmesan cheese. Add cooled sausage and cooled mushroom stems. Stir mixture together and refrigerate for a short time to firm up.
Spoon mixture into the cavity of each mushroom, creating a sizable mound over the top. Bake at 350 degrees for 20 minutes or until golden brown. Broil for 1-2 minutes to get tops browned. Allow to cool at least ten minutes before serving; the stuffed mushrooms taste better when not piping hot.