Stuffed White Mushrooms with Pecans

Name: Stuffed White Mushrooms with Pecans
Ingredients: 1/8 cup extra-virgin olive oil; 1 yellow onion, peeled and finely diced; Kosher salt; Freshly ground white pepper; 2 small cloves garlic, grated; 40 large white mushrooms, stemmed; 1/4 cup dry Vermouth or dry white wine; 1 cup sour cream; 2 tablespoons toasted breadcrumbs; 1/2 cup Parmesan cheese, grated; 1/2 cup Fisher® Pecan Halves, coarsely chopped; 1 to 1 1/2 cups loose breadcrumbs, toasted; 1 tablespoon balsamic vinegar or lemon juice for finishing (optional)