2 tbsp. butter
1/2 finely chopped onion
20 button mushrooms, stemmed and chopped
2 cloves garlic, minced
1 tbsp. finely chopped parsley, plus more for garnish
1/2 c. breadcrumbs, plus more for sprinkling
1/2 c. grated Parmesan
Freshly ground black pepper
Extra-virgin olive oil, for drizzling
Preheat oven to 350°. In a large skillet, melt butter. Add onion, mushroom stems, garlic, and parsley.
In a small bowl, mix together Boursin, breadcrumbs, grated Parmesan, and mushroom stem mixture and season with salt and pepper.
Stuff mushrooms and sprinkle with more breadcrumbs and drizzle with olive oil.
Garnish with finely chopped parsley and bake until mushrooms are deeply golden and cooked through, 20 minutes.