stuffed mushroom recipe

Ingredients: 1 pound white or cremini mushrooms, stems removed 1/4 cup finely chopped onion 2 cloves garlic, minced 1/2 cup breadcrumbs 1/2 cup grated Parmesan cheese 1/4 cup chopped fresh parsley 1/4 cup cream cheese, softened 2 tablespoons olive oil 1/2 teaspoon salt 1/4 teaspoon black pepper