Ingredient:

• 12 lasagna noodles
• 2 tablespoons olive oil
• 1 pound fresh mushrooms, finely chopped
• 1/4 cup dry white wine
• 1 large egg, lightly beaten
• 2 cups shredded mozzarella cheese, divided
• 1 carton (15 ounces) whole-milk ricotta cheese
• 1/2 cup grated Parmesan cheese, divided
• 4 green onions, chopped
• 1 teaspoon grated lemon zest
• 2 tablespoons lemon juice
• 1 teaspoon kosher salt, divided
• 3 tablespoons butter
• 3 tablespoons all-purpose flour
• 3 cups whole milk
• Dash ground nutmeg
• Chopped fresh parsley, optional