Preheat your oven to 375°F (190°C).
In a bowl, mix together the cream cheese, Parmesan cheese, parsley, chives, garlic, salt, and pepper until well combined.
Fill each mushroom cap with the cheese mixture, pressing gently to ensure the filling is secure.
Arrange the stuffed mushrooms on a baking sheet.
Bake for 15-20 minutes, or until the mushrooms are tender and the tops are golden.
Serve warm as an appetizer or party snack.