Baked Mushroom Spinach and Chicken Gnocchi

Ingredients

• - 1 tablespoon olive oil
• - 1 (8 ounce) package sliced fresh mushrooms
• - salt and ground black pepper to taste
• - 2 tablespoons unsalted butter
• - 2 tablespoons all-purpose flour
• - 1 ½ cups whole milk
• - 1 cup chicken broth
• - ½ teaspoon salt
• - ¼ teaspoon ground nutmeg
• - ½ (3 pound) rotisserie chicken
• boned and shredded
• - 1 (16 ounce) package potato gnocchi
• - 2 cups baby spinach
• - ¼ cup grated Parmesan cheese