Chicken Spinach Alfredo Casserole

Picture a bubbling casserole crowned with bronzed mozzarella, ribbons of emerald spinach peeking through creamy, ivory-silk Alfredo, and the comforting aroma of garlic and Parmesan drifting through the kitchen.

Imagine fork-tender pasta and juicy chicken nestled in a velvety sauce that clings to every curve—rich, cozy, and exactly what you crave when the day runs long.

This dish matters to me because it’s the kind of hug-in-a-pan that turns an ordinary evening into something you’ll linger over. It bridges convenience and comfort: pantry-friendly, crowd-pleasing, and easy to prep ahead.

It shines on busy weeknights when you need dinner to deliver, yet feels at home on slow Sunday suppers, potlucks, or drop-by guests nights.

When my son’s practice ran late and everyone was famished, this casserole came out of the oven bubbly and golden just as backpacks hit the floor—problem solved. Ready? Let’s cook!

Why You’ll Love It

• Delivers creamy, garlicky comfort with tender chicken and spinach
• Bakes fast for weeknights; prep-to-table in under an hour
• Uses simple, affordable pantry and grocery staples
• Kid-friendly flavors; mild heat optional with red pepper
• Flexible add-ins: mushrooms, sun-dried tomatoes, or rotisserie chicken

Ingredients

• 12 ounces pasta, penne or rotini — cook 2 minutes shy for best texture
• 2 tablespoons olive oil — choose extra-virgin for flavor
• 1.5 pounds boneless skinless chicken breasts, cut into 1-inch cubes — trim well for even browning
• 1 teaspoon kosher salt — season chicken evenly
• 0.5 teaspoon black pepper — freshly ground preferred
• 3 tablespoons unsalted butter — prevents sauce from being too salty
• 4 cloves garlic, minced — sauté just until fragrant
• 3 tablespoons all-purpose flour — for a smooth blonde roux
• 2 cups whole milk, warmed — helps prevent lumps
• 1 cup heavy cream, warmed — for a richer Alfredo
• 1 cup grated Parmesan cheese, divided — use real Parmigiano-Reggiano
• 0.5 teaspoon Italian seasoning — adds herbal depth
• 0.25 teaspoon crushed red pepper flakes (optional) — for gentle heat
• 5 ounces baby spinach, roughly chopped — wilts into the sauce
• 1 cup shredded mozzarella cheese — part-skim melts stretchy
• 0.25 cup chopped fresh parsley (optional) — bright, fresh finish

Step-by-Step Method

Preheat the Oven and Prep the Dish

Preheat oven to 375°F. Grease a 9×13-inch baking dish.

Warm milk and cream in a small saucepan over low heat. Set aside. Gather equipment and ingredients. Chop spinach and parsley. Cube chicken into 1-inch pieces. Grate Parmesan and shred mozzarella. This prep guarantees smooth cooking and an even bake.

Parboil the Pasta

Bring a large pot of salted water to a boil. Add pasta and cook until 2 minutes shy of package directions.

Stir occasionally to prevent sticking. Drain in a colander and set aside. Slightly undercooking keeps pasta from becoming mushy as it finishes in the oven with the sauce and cheese.

Sear the Chicken

Heat olive oil in a large skillet over medium-high heat. Season chicken with kosher salt and black pepper.

Sear, stirring occasionally, until just cooked through, 5 to 7 minutes. Avoid overcooking to keep it juicy. Transfer chicken to a plate. Keep skillet drippings for added flavor if desired.

Start the Garlic Butter

Melt unsalted butter in a medium saucepan over medium heat. Add minced garlic.

Cook, stirring, until fragrant, about 30 seconds. Don’t brown the garlic. Keep heat moderate to avoid scorching. This step builds a flavorful base for the Alfredo sauce and balances richness with aromatic depth.

Build a Blonde Roux

Whisk in all-purpose flour.

Cook, whisking constantly, for 1 minute until foamy and pale. Don’t let it darken. Cooking the flour removes raw taste and prepares it to thicken the sauce. Maintain steady heat. Keep whisk moving to prevent lumps and ensure a smooth, velvety texture later.

Whisk in Dairy and Thicken

Gradually whisk in warmed milk and heavy cream.

Add in a slow stream to avoid lumps. Cook, whisking frequently, until the sauce thickens enough to coat the back of a spoon, 4 to 6 minutes. Adjust heat to maintain a gentle simmer. Aim for silky, pourable consistency without boiling.

Finish the Alfredo Sauce

Remove saucepan from heat. Stir in 3/4 cup grated Parmesan, Italian seasoning, and crushed red pepper flakes if using.

Mix until smooth and melted. Taste and season with salt and pepper. Off-heat finishing prevents graininess and keeps the sauce glossy. Set aside while assembling.

Combine Pasta, Chicken, and Spinach

Add drained pasta to a large bowl. Top with cooked chicken and chopped baby spinach.

Pour Alfredo sauce over. Toss until evenly coated and spinach wilts slightly. Work quickly to keep everything warm. Guarantee sauce reaches into pasta tubes or spirals for consistent flavor in each bite.

Assemble in the Baking Dish

Transfer the mixture to the prepared baking dish. Spread into an even layer.

Sprinkle shredded mozzarella evenly over the top. Add remaining 1/4 cup Parmesan. Tap dish gently to settle contents. This layering delivers a melty, golden lid that seals in moisture and enhances browning.

Bake Covered, Then Uncovered

Cover loosely with aluminum foil. Bake for 15 minutes.

Remove foil and continue baking 8 to 10 minutes until bubbly and golden on top. Watch closely to avoid over-browning. If needed, broil briefly for extra color. The two-stage bake ensures a creamy interior and crisp-cheesy finish.

Rest, Garnish, and Serve

Let the casserole rest for 5 minutes to set. Sprinkle with chopped fresh parsley if desired.

Slice or spoon into portions and serve hot. Pair with a crisp salad or garlic bread. Refrigerate leftovers promptly. Reheat gently, covered, to maintain creaminess. Enjoy a cozy, crowd-pleasing dinner.

Ingredient Swaps

• Pasta: Use whole-wheat or chickpea pasta for more fiber/protein; gluten-free penne/rotini for GF.
• Chicken: Swap with rotisserie chicken or leftover turkey; use Italian sausage or cooked shrimp; for vegetarian, use white beans or sautéed mushrooms.
• Dairy: Substitute half-and-half for cream (lighter) or cream cheese for extra richness; use lactose-free milk/cream and Parmesan-style hard cheese; for dairy-free, use unsweetened oat milk + coconut cream and vegan Parmesan/mozzarella.
• Flour: Replace with gluten-free all-purpose blend or 1:1 cornstarch slurry for the sauce.
• Spinach: Use kale (chopped, briefly sautéed), Swiss chard, or frozen spinach (thawed, well-squeezed).
• Cheeses: Budget swap pre-shredded mozzarella and grated Parmesan; regional swap Pecorino Romano or Grana Padano.
• Seasoning: Italian seasoning can be replaced with oregano-basil-thyme mix; add sun-dried tomatoes or roasted red peppers for variety.

You Must Know

Doneness • If the Alfredo sauce looks thin after thickening, keep it on gentle heat and stir until it coats the back of a spoon and a finger swipe leaves a clean line, about 4–6 minutes; this guarantees it won’t weep in the oven.

Troubleshoot • When the sauce turns grainy after adding Parmesan, stir in 1–2 tablespoons warm cream off heat and agitate until smooth; the added moisture/fat helps re-emulsify without overheating the cheese.

Flavor Boost • For deeper savory notes, season the chicken cubes with 1 teaspoon garlic powder and 1/2 teaspoon smoked paprika 15 minutes ahead; the spice bloom plus Maillard browning boosts flavor without extra salt.

Scale • For 9–10 servings, increase all ingredients by 50% and use a 12×18-inch pan; extend the covered oven time to about 22–25 minutes before uncovering, checking for bubbling at edges as the doneness cue.

Make-Ahead • To assemble a day early, cool the sauce to room temp before combining, then chill the casserole covered; bake straight from fridge, adding 10–15 minutes to the covered time until center hits 165°F.

Serving Tips

• Serve with garlic bread or buttery breadsticks to soak up extra sauce.
• Add a bright side salad with lemon vinaigrette to cut richness.
• Garnish with extra Parmesan, cracked pepper, and chopped parsley for freshness.
• Plate alongside roasted broccoli or asparagus for color and crunch.
• Offer red pepper flakes and lemon wedges for customizable heat and zing.

Storage & Make-Ahead

Refrigerate leftovers in an airtight container for 3–4 days.

Reheat covered at 350°F or microwave with a splash of milk to keep it creamy.

Assemble up to 24 hours ahead.

Bake straight from the fridge, adding 10–15 minutes covered.

Freeze for 2–3 months.

Thaw overnight in the refrigerator before reheating.

Reheating

Reheat gently: microwave covered portions with a splash of milk, stirring midway.

Oven at 325°F, covered, until warmed through.

Stovetop on low with a little cream, stirring often to prevent drying.

Church Potluck Staple

Nothing brings a crowd together like a bubbling, golden casserole, and this Chicken Spinach Alfredo version earns a prime spot on any church potluck table.

I carry it in, still warm under foil, and watch heads turn at the aroma of garlic, cream, and Parmesan. It’s familiar yet special—tender chicken, silky sauce, spinach tucked between curls of pasta, and that cheesy crown.

I plan for six servings per pan, but it stretches easily with a simple side salad and rolls.

For smooth service, I bake it just before leaving, then keep it covered; it holds heat beautifully. Want a time-saver? Rotisserie chicken works. For variety, I’ll add sun-dried tomatoes or sautéed mushrooms. Either way, it scoops clean, comforts quickly, and disappears fast.

Final Thoughts

Give this Chicken Spinach Alfredo Casserole a try and make it your own—swap in your favorite pasta, add veggies like mushrooms or sun-dried tomatoes, or use rotisserie chicken for a quick win.

Can’t wait to hear how you tweak it!

Frequently Asked Questions

Is This Casserole Freezer-Friendly Before Baking?

Yes—freeze it unbaked. I cool everything, assemble, skip the parsley, wrap tightly, and freeze up to 2 months. Bake from frozen, covered, at 375°F about 35–45 minutes, then uncover to bubble and bronze. You’ll love it.

Can I Make It Gluten-Free Without Sacrificing Texture?

Yes—you can. I’d use sturdy gluten-free penne, whisk in a 1:1 gluten-free flour for the roux, and choose GF broth and seasonings. The sauce stays silky, the bake holds beautifully, and nobody misses gluten.

What Wine Pairs Best With This Dish?

I’d pour a crisp, lemon‑kissed Pinot Grigio or Soave. If you crave richness, I’d pick lightly oaked Chardonnay. Prefer red? I’d choose Pinot Noir, chilled slightly. Each cut creamy sauce, brighten spinach, and flatter tender chicken.

How Do I Prevent a Greasy Alfredo Sauce?

Keep it silky by warming dairy, removing the pan from heat before adding Parmesan, and whisking gently. I avoid overheating, add butter after thickening, and drain excess chicken fat. If it breaks, I whisk in a splash of warm milk.

Can I Cook It in an Air Fryer Oven?

Yes—you can. I’d use a shallow, oven-safe pan, 350°F, and cook covered 12–15 minutes, then uncover to brown 6–8 minutes. Don’t overcrowd; circulate air. I’d watch for bubbling edges and golden cheese. Enjoy.