Spinach Gratin Recipe

Ingredients

• 20 ounces frozen chopped spinach
• 3 tablespoons salted butter
• 3 tablespoons chopped onion
• 3 tablespoons minced garlic, about 3 large cloves
• 3 tablespoons all-purpose flour
• 1½ cups half-and-half
• 1 teaspoon onion powder
• 1 teaspoon Italian seasoning
• 3/4 teaspoon garlic powder
• 1/4 teaspoon ground nutmeg
• 1 pinch cayenne, optional
• 4 ounces cream cheese, room temperature
• 2/3 cup shredded Parmesan cheese, divided
• 3/4 cup shredded Italian blend cheese, divided
• kosher salt and freshly ground black pepper, to taste
• 1/4 cup panko breadcrumbs