Preheat your oven to 375°F (190°C). Clean the mushrooms and remove the stems, scraping out the gills carefully.

Sauté chopped mushroom stems and minced garlic in olive oil for 3-4 minutes. Combine with cream cheese, beef, Parmesan, parsley, salt, and pepper in a bowl.

Fill each mushroom cap with the creamy filling, heaping it above the rim, and press an olive on top.

Arrange the stuffed mushrooms on a baking sheet, brush with olive oil, and bake for 20-25 minutes until golden.

Garnish with red bell pepper slivers or Sriracha, serve warm or at room temperature.