Creamy Chicken and Spinach Lasagna Casserole

Quick Recipe Version (TL;DR)

• Yield: 8 servings
• Prep Time: 30 minutes
• Cook Time: 45 minutes
• Total Time: 1 hour 15 minutes (plus 15 minutes resting)

Quick Ingredients

• 9 dry lasagna noodles
• 3 cups cooked shredded chicken (about 1 lb)
• 1 tablespoon olive oil (plus more for pan)
• 1 small yellow onion, finely chopped
• 3 cloves garlic, minced
• 10 ounces fresh baby spinach
• 15 ounces whole-milk ricotta cheese
• 1 large egg
• 1 1/4 cups finely grated Parmesan cheese, divided
• 3 cups shredded low-moisture mozzarella cheese (about 12 ounces)
• 3 cups marinara sauce
• 1 cup heavy cream
• 1 teaspoon Italian seasoning
• 1/2 teaspoon garlic powder
• 1/2 teaspoon kosher salt, plus more for pasta water
• 1/2 teaspoon black pepper
• 1/4 teaspoon ground nutmeg (optional)
• Pinch red pepper flakes (optional)
• Fresh basil or parsley, for garnish

Do This

• 1. Preheat oven to 375°F (190°C). Boil lasagna noodles in salted water until very al dente (about 7–8 minutes). Drain, rinse briefly with cool water, and toss with a little olive oil so they do not stick.
• 2. For the filling, sauté onion in olive oil until soft, add garlic, then wilt the spinach. Cool slightly. In a large bowl, mix ricotta, egg, 1 cup Parmesan, salt, pepper, nutmeg, chicken, and the spinach mixture.
• 3. For the sauce, gently simmer marinara, heavy cream, Italian seasoning, garlic powder, and red pepper flakes for 5–10 minutes. Adjust salt and pepper.
• 4. Lightly oil a 9×13-inch baking dish. Spread about 3/4 cup sauce on the bottom. Layer: 3 noodles, half the chicken-spinach filling, about 3/4–1 cup sauce, and 1 cup mozzarella. Repeat once more.
• 5. Top with final 3 noodles, the remaining sauce, 1 cup mozzarella, and 1/4 cup Parmesan. Cover tightly with foil (sprayed with cooking spray so it does not stick to the cheese).
• 6. Bake 25 minutes covered, then uncover and bake 15–20 minutes until bubbly and golden. Rest 15 minutes before slicing. Garnish with fresh herbs and serve.

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Why You’ll Love This Recipe

• Classic comfort food flavor with a lighter twist from tender shredded chicken instead of heavy beef or sausage.
• A creamy ricotta and spinach layer adds veggies and richness without feeling fussy.
• Uses mostly pantry and grocery-store staples but bakes up like a special-occasion casserole.
• Perfect for making ahead, feeding a crowd, or stocking the freezer for busy weeknights.

Grocery List

• Produce: 1 small yellow onion, 3 cloves garlic, 10 ounces fresh baby spinach, fresh basil or parsley (for garnish)
• Dairy: 15 ounces whole-milk ricotta, 3 cups shredded mozzarella (about 12 ounces), 1 1/4 cups finely grated Parmesan, 1 cup heavy cream, 1 large egg
• Pantry: 9 dry lasagna noodles, 3 cups marinara sauce (jarred or homemade), olive oil, kosher salt, black pepper, Italian seasoning, garlic powder, ground nutmeg (optional), red pepper flakes (optional), nonstick cooking spray (optional, for foil)

Full Ingredients

For the Chicken and Spinach Filling

• 1 tablespoon olive oil
• 1 small yellow onion, finely chopped (about 1 cup)
• 3 cloves garlic, minced
• 10 ounces fresh baby spinach (about 8–10 packed cups)
• 3 cups cooked shredded chicken (about 1 pound cooked; rotisserie or poached)
• 15 ounces whole-milk ricotta cheese (about 1 3/4 cups)
• 1 large egg
• 1 cup finely grated Parmesan cheese (from the 1 1/4 cups total), divided use
• 1/2 teaspoon kosher salt
• 1/2 teaspoon freshly ground black pepper
• 1/4 teaspoon ground nutmeg (optional but delicious with spinach)

For the Creamy Tomato Sauce

• 3 cups marinara sauce (about 24 ounces)
• 1 cup heavy cream
• 1 teaspoon Italian seasoning
• 1/2 teaspoon garlic powder
• Pinch red pepper flakes (optional, for gentle heat)
• Kosher salt and black pepper, to taste

For the Lasagna Assembly

• 9 dry lasagna noodles (regular, not no-boil)
• 2 tablespoons olive oil, divided (for noodles and greasing the pan)
• 3 cups shredded low-moisture mozzarella cheese (about 12 ounces)
• 1/4 cup finely grated Parmesan cheese (remaining from the 1 1/4 cups total)
• Fresh basil or flat-leaf parsley, chopped, for garnish
• Nonstick cooking spray (optional, for coating foil)

Step-by-Step Instructions

Step 1: Cook the Noodles and Preheat the Oven

Preheat your oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish with about 1 teaspoon of olive oil and set aside.

Bring a large pot of well-salted water to a boil. Add the 9 lasagna noodles and cook until very al dente, about 7–8 minutes (they will finish cooking in the oven). Stir occasionally so they do not stick.

Drain the noodles in a colander and quickly rinse with cool water just until they are comfortable to handle. Lay them flat on a lightly oiled baking sheet or a piece of parchment paper. Drizzle with another teaspoon or so of olive oil and gently toss or rub so they do not stick together.

Step 2: Make the Chicken and Spinach Ricotta Filling

While the noodles cook, heat 1 tablespoon olive oil in a large skillet over medium heat. Add the chopped onion and cook, stirring occasionally, until softened and translucent, about 4–5 minutes. Add the minced garlic and cook for 30 seconds, just until fragrant.

Add the baby spinach to the skillet in batches, tossing frequently, until all of it is wilted and most of the moisture has evaporated, about 3–4 minutes. Remove from heat and let cool for a few minutes. If the spinach seems very wet, you can roughly chop it and press it gently with a paper towel to remove excess moisture.

In a large mixing bowl, combine the ricotta, egg, 1 cup of the grated Parmesan, kosher salt, black pepper, and nutmeg (if using). Stir until smooth and well combined. Add the shredded chicken and the slightly cooled spinach-onion mixture. Mix until everything is evenly distributed. Taste and adjust salt and pepper if needed (remember the sauce and cheeses are also salty).

Step 3: Prepare the Creamy Tomato Sauce

In a medium saucepan, combine the marinara sauce and heavy cream. Stir in the Italian seasoning, garlic powder, and red pepper flakes (if using).

Place the saucepan over medium heat and bring the mixture just to a gentle simmer, then reduce the heat to low. Let it simmer for 5–10 minutes, stirring occasionally, to thicken slightly and allow the flavors to meld. Taste and season with additional salt and pepper as needed. Turn off the heat and set aside.

Step 4: Assemble the First Layers

Spread about 3/4 cup of the creamy tomato sauce evenly over the bottom of your prepared 9×13-inch baking dish. This helps prevent sticking and keeps the bottom layer moist.

Lay 3 lasagna noodles over the sauce, slightly overlapping if needed to cover the bottom completely. Spoon half of the chicken and spinach filling over the noodles and spread it out into an even layer, all the way to the edges so you get filling in every bite.

Pour about 3/4 to 1 cup of sauce over the filling and spread gently. Sprinkle 1 cup of shredded mozzarella evenly over the top.

Step 5: Build the Remaining Layers

Place another 3 noodles over the cheese to form the second noodle layer. Spread the remaining half of the chicken and spinach filling evenly over these noodles. Pour another 3/4 to 1 cup of sauce on top and gently spread.

Sprinkle another 1 cup of mozzarella over this layer.

Finish with the final 3 noodles. Pour all of the remaining sauce over the top, spreading it so it fully covers the noodles (this keeps the top from drying out). Sprinkle the remaining 1 cup of mozzarella cheese and the remaining 1/4 cup grated Parmesan evenly over the surface.

Step 6: Bake the Lasagna

Cover the baking dish tightly with aluminum foil. For best results, lightly spray the underside of the foil with nonstick cooking spray so it does not stick to the cheese.

Bake the covered lasagna at 375°F (190°C) for 25 minutes. Then carefully remove the foil and return the dish to the oven. Bake uncovered for an additional 15–20 minutes, or until the sauce is bubbling around the edges and the top is melted, golden-brown, and slightly crisp in spots.

If you like an extra browned top, you can broil the lasagna for 1–2 minutes at the end, watching very closely so it does not burn.

Step 7: Rest, Slice, and Serve

Once the lasagna is done, remove it from the oven and place the dish on a cooling rack. Let it rest for at least 15 minutes before cutting. This resting time allows the layers to set so you can slice neat squares instead of having everything slide apart.

Sprinkle chopped fresh basil or parsley over the top for color and freshness. Cut into 8 squares and serve warm. Pair it with a simple green salad and some crusty bread if you like.

Pro Tips

• Use rotisserie chicken to save time. Shredded meat from a store-bought rotisserie chicken works perfectly and builds in extra flavor with almost no effort.
• Do not overcook the noodles. Aim for very al dente pasta since it will continue to cook and absorb moisture in the oven. Overcooked noodles can turn mushy in the finished lasagna.
• Let it rest before slicing. That 15-minute rest feels long when you are hungry, but it is the difference between tidy layers and a soupy casserole.
• Adjust creaminess to your taste. For a lighter sauce, use half-and-half instead of heavy cream. For extra richness, add a tablespoon of butter to the sauce while it simmers.
• Spinach options. You can swap in 10 ounces of frozen chopped spinach, thawed and very well squeezed dry, if fresh spinach is not available.

Variations

• White chicken lasagna: Replace the marinara with 3 cups of Alfredo sauce (homemade or store-bought) and omit the Italian seasoning and red pepper flakes. Keep the spinach and chicken filling as written.
• Pesto chicken and spinach lasagna: Stir 1/3 cup basil pesto into the ricotta mixture and use a mix of marinara and pesto (2 1/2 cups marinara + 1/2 cup pesto) for a fragrant, herb-forward twist.
• Extra veggie version: Add thinly sliced sautéed mushrooms or roasted zucchini slices in a layer over the ricotta mixture for more vegetables and texture.

Storage & Make-Ahead

Allow leftover lasagna to cool completely, then cover the baking dish tightly or transfer slices to airtight containers. Refrigerate for up to 4 days. Reheat individual portions in the microwave until hot, or warm a larger portion in a 325°F (165°C) oven, covered, for 20–25 minutes.

To freeze, cool the baked lasagna completely, wrap well (first in plastic wrap, then in foil), and freeze for up to 3 months. Thaw overnight in the refrigerator, then reheat covered at 350°F (175°C) for 30–40 minutes, until heated through.

For make-ahead prep, assemble the lasagna completely, cover tightly, and refrigerate for up to 24 hours before baking. Add 5–10 extra minutes to the covered baking time if you are starting from cold. You can also freeze the assembled but unbaked lasagna; thaw overnight in the fridge before baking as directed.

Nutrition (per serving)

Approximate values per serving (1/8 of the pan): about 650 calories, 40 g protein, 35 g fat, 40 g carbohydrates, 2 g fiber, and 1150 mg sodium. Actual nutrition will vary based on the specific brands of sauce, cheese, and chicken you use.