Healthy Green Bean Casserole

Bahan-bahan (10 porsi)

• 1/2 cup whole wheat panko breadcrumbs
• 1/4 cup freshly grated Parmesan cheese
• 2 tablespoons chopped fresh parsley (plus additional for garnish)
• 4 tablespoons extra-virgin olive oil (divided)
• 2 1/2 pounds green beans (trimmed)
• 1 medium onion (very thinly sliced)
• 8 ounces baby bella (cremini) mushrooms (sliced (do not use plain white mushrooms, as they do not have much flavor))
• 3 tablespoons all-purpose flour
• 2 cups 2% milk
• 1 teaspoon kosher salt
• 1/2 teaspoon ground black pepper
• 1/8 teaspoon ground nutmeg
• 7 ounces 2% Greek yogurt