Preheat oven to 350°F (175°C). Clean mushrooms using a damp cloth. Remove stems and set aside both caps and stems.

Finely chop mushroom stems and reserve.

In a skillet over medium heat, cook and crumble the beef sausage until browned. Remove and let cool.

In the same skillet, sauté onion and garlic for 2 minutes. Add broth to deglaze the pan and let it reduce.

Add chopped mushroom stems, cook for another 2 minutes, then season with salt and pepper. Let cool.

In a bowl, mix cream cheese, egg yolk, and Parmesan cheese. Add cooled sausage and mushroom mixture. Stir well.

Refrigerate the mixture briefly to firm it up.

Fill each mushroom cap generously with the mixture, forming a mound.

Arrange on a baking sheet and bake for 20–25 minutes until golden brown.

Let cool slightly before serving. This stuffed mushrooms recipe tastes best when warm, not piping hot.