Preheat your oven to 375°F (190°C). Line a baking sheet with parchment paper.
In a skillet over medium heat, add 1 tablespoon of olive oil. Sauté the onion and garlic until translucent.
Mix in the chopped mushroom stems and cook until they’re soft and the moisture has evaporated.
Remove from heat and let the mixture cool slightly. Stir in the cream cheese, Parmesan, breadcrumbs, parsley, thyme, and Worcestershire sauce—season with salt and pepper.
Fill each mushroom cap with a generous spoonful of the stuffing mixture, pressing it down slightly.
Place the stuffed mushrooms on the prepared baking sheet. Brush the tops with olive oil and sprinkle with shredded mozzarella cheese.
Bake for 20-25 minutes until the mushrooms are tender and the tops are golden brown.
Active Prep: 20 minutes
Cooking Time: 20-25 minutes
Total Time: 40-45 minutes
Servings: Makes 24 stuffed mushrooms
Kcal: Approximately 50 kcal per stuffed mushroom