Pesto Portabella Burgers on Sourdough Bread

The entire family will enjoy these easy-to-make mushroom burgers! Recipe Nutritional Information: Servings: 4 Estimated Total Preparation Time: 16 minutes Calories per Serving: 532 Recipe Ingredients: 2 tbsp fresh basil, chopped 1/4 cup walnuts, chopped 1/4 cup light...