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A slice of white chicken lasagna on a plate next too another plate of lasagna and a casserole dish.
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4.96 from 71 votes

White Chicken Spinach Lasagna

This easy White Chicken Lasagna is loaded with layers of tender lasagna noodles, chunks of rotisserie chicken, savory mushrooms, earthy spinach, a creamy homemade white sauce and cheese! It's freezer-friendly, homey and delicious with all the vibes of a classic lasagna but made with white sauce, chicken, and vegetables instead.
Prep Time20 minutes
Cook Time40 minutes
Total Time1 hour
Course: Dinner
Cuisine: American
Servings: 12 servings
Calories: 503kcal
Author: Amy Nash

Ingredients

Sauce

  • 2 Tablespoons salted butter
  • 2 tablespoons olive oil
  • 1 medium onion, chopped
  • 2 cloves garlic, minced
  • 16 ounces crimini mushrooms, sliced
  • 6 Tablespoons all-purpose flour
  • 2 cups chicken broth
  • 1 ½ cups milk
  • 1 teaspoon dried basil
  • 1 teaspoon dried oregano
  • 1 teaspoon salt
  • ½ teaspoon black pepper
  • ½ teaspoon crushed red pepper flakes
  • ½ teaspoon fennel seed
  • 8 ounces baby spinach

Assembly

  • 12 whole lasagna noodles, cooked according to package directions
  • 3-4 cups cooked chicken, about 2 pounds shredded or cubed (we like to use a rotisserie chicken)
  • 4 cups mozzarella cheese, shredded
  • 15 ounces ricotta cheese (about 2 cups)
  • cups grated Parmesan cheese, divided
  • Parsley chopped for sprinkling on top, optional

Instructions

  • Place lasagna noodles in a 9x13-inch baking dish. Cover with very hot water and let soak while preparing the sauce. Alternatively, you can prepare the noodles by boiling them according to the package directions.

Sauce

  • In a large saucepan, melt butter with the oil over medium heat. Then add the chopped onion and garlic and cook together until softened, about 3-4 minutes. Add the sliced mushrooms and cook for another 6-8 minutes, stirring occasionally, until the mushrooms have softened and released some of their liquid. Sprinkle the flour over the softened onions and mushrooms, then stir to combine, cooking for another 1-2 minutes so the flour can absorb the liquid.
  • Whisk chicken broth and milk into the vegetables, stirring until the sauce simmers and thickens, about 4-5 minutes. Stir in the basil, oregano, salt, pepper, red pepper flakes, and fennel seed.
  • Add the spinach to the sauce (you may have to do this in handfuls) and stir until wilted. Sprinkle with ½ cup of the Parmesan cheese over the sauce and stir to combine. Remove the sauce from the heat and set aside.

Assembly

  • Drain lasagna noodles and set aside.
  • Spread a few spoonfuls of the sauce on the bottom of a large 9x13-inch baking dish. Arrange four of the softened lasagna noodles over the sauce. Spread ½ of the ricotta cheese over the noodles, then sprinkle with ½ of the chopped rotisserie chicken.
  • Spoon about ⅓ of the mushroom and spinach sauce over the chicken, then sprinkle with ⅓ of the mozzarella and Parmesan cheese.
  • Repeat layers by arranging four more of the lasagna noodles on top of the cheese, followed by the remaining ricotta cheese, remaining chicken, and ⅓ of the sauce and cheeses.
  • Finish the lasagna by arranging the last four lasagna noodles on top. Cover the noodles with the remaining sauce and sprinkle with the last of the mozzarella and Parmesan cheese on top.
  • Bake at 350°F for 35 to 40 minutes until hot and bubbly, finishing under the broiler just to add a little color to the top, but be careful not to burn the cheese. Let the lasagna stand for at least 10 minutes before slicing and serving. Sprinkle with freshly chopped parsley, if desired.

Notes

  • Make-Ahead: Lasagna can be made a day in advance and refrigerated. Just add 15 minutes to the baking time, and cover with aluminum foil for the first 20 minutes of baking.
  • Freezer Meal Prep: Wrap and freeze the unbaked lasagna with aluminum foil. When ready to bake, you can bake from frozen for about 2 hours until heated through, keeping it covered with aluminum foil for the first 1 hour and 15 minutes.
  • Storage: Store in an airtight container or covered tightly with plastic wrap or aluminum foil in the fridge for up to 4 days. Reheat it in the oven as before, covered with foil, or in the microwave.
  • Freezing Leftovers: Store the baked and cooled lasagna in an airtight container or freezer bag for up to 3 months. When you're ready to reheat it, allow it to thaw in the refrigerator overnight, and then bake it in the oven as before, covered with foil. 
  • Substitutions: You could use 1 package of frozen spinach in place of the fresh spinach. Just defrost and squeeze out as much water as you can.
  • Original Version: This recipe was modified in 2023 to reflect how we most often make it these days. The original version was almost the same, except we browned 1 pound of ground chicken with the mushrooms, which were minced instead of sliced and not included in the sauce as they are here. Also, the spinach was cooked separately until wilted, rather than being added to the sauce as it is now. The flavors and amounts all remain the same - I just updated the method to make it easier and more approachable using a rotisserie chicken.

Nutrition

Calories: 503kcal | Carbohydrates: 33g | Protein: 33g | Fat: 27g | Saturated Fat: 14g | Polyunsaturated Fat: 2g | Monounsaturated Fat: 9g | Trans Fat: 0.2g | Cholesterol: 102mg | Sodium: 931mg | Potassium: 697mg | Fiber: 2g | Sugar: 3g | Vitamin A: 4299IU | Vitamin C: 11mg | Calcium: 494mg | Iron: 3mg