• Preheat the oven to 375°F.
• In a large pot of salted boiling water, cook the lasagna noodles until al dente according to package directions. Drain then return to the pot and set aside. Add olive oil to the boiling water along with the salt if desired, or drizzle over the noodles to prevent sticking after draining.
  9 lasagna noodles
• Using your hands, or two forks, shred the white and dark meat from a rotisserie chicken and set aside.
  3½ cups shredded chicken

Spinach cream sauce

• In a 3-quart sauce pan over medium heat, add the salted butter, onion, garlic, garlic powder, and salt. Cook for 2-3 minutes until the onions are translucent and the garlic is fragrant.
  6 tablespoons salted butter, ¾ cup yellow onion, 1 tablespoon fresh garlic, finely minced, 1 teaspoon garlic powder, ½ teaspoon salt
• Whisk in the all-purpose flour until fully absorbed by the butter. While whisking constantly, slowly add the chicken broth and heavy cream until fully incorporated and no lumps of flour remain. Bring the sauce to a boil, reduce the heat to low and allow it to simmer for 2-3 minutes or until thickened. Be sure to whisk the sauce often to ensure it does not clump or burn.
  ¼ cup all-purpose flour, 1¼ cups chicken broth, 1¼ cups heavy cream
• Remove the sauce from the heat, stir in the parmesan cheese until fully incorporated. Add the baby spinach stirring until fully incorporated and the spinach has wilted completely into the sauce. Set aside to cool slightly while preparing the ricotta cheese mixture.
  1 cup shredded parmesan cheese, 3 cups lightly packed baby spinach

Ricotta cheese mixture

• Stir together in a large bowl the ricotta cheese, egg, 2 ½ cups shredded mozzarella cheese, salt, and black pepper until well combined. Set aside.
  15 ounce container whole milk ricotta cheese, 1 large egg, 2.5 cups shredded whole milk mozzarella cheese, ½ teaspoon salt, ¼ teaspoon black pepper

Assembling the white chicken lasagna

• To the bottom of a deep sided 9x13 baking dish, evenly spread ½-¾ cup of the spinach cream sauce then place three of the cooked lasagna noodles evenly into the bottom of the dish.
• Top the noodles with half the reserved ricotta cheese mixture being sure to carefully spread out into an even layer.
• Sprinkle half the shredded chicken evenly over the ricotta cheese layer then spoon a third of the remaining spinach cream sauce over the chicken.
• Place down three more lasagna noodles, the remaining ricotta cheese mixture and the remaining shredded chicken. Top with another third of the sauce, followed by the remaining three noodles and the final third of the sauce.
• Sprinkle the remaining 1 ½ cups shredded mozzarella cheese evenly over the top then bake for 25-30 minutes or until the sauce is bubbly and the cheese is melted and lightly golden on the top.
  1.5 cups shredded whole milk mozzarella cheese
• Remove the white chicken lasagna from the oven and let it cool at room temperature for 15-20 minutes to allow the sauce to cool slightly and set before slicing and serving. Garnish with a light sprinkle of chopped fresh parsley if desired before serving.
  Chopped fresh parsley