Creamy Chicken, Spinach and Mushroom Casserole Recipe

I have a confession to make. I didn’t always appreciate a good casserole.

They seemed too simple, maybe a little dated, just a bit too practical for my taste. That changed on a chilly evening with some leftover roasted chicken in the fridge.

I wanted something comforting, but new. A meal that felt special without needing hours of work.

The result was this dish, a creamy chicken, spinach, and mushroom casserole. It completely changed my mind.

This casserole is everything you need it to be. Rich, satisfying, and full of flavor, yet it comes together with a wonderful, unhurried ease. It’s the kind of food that makes a weeknight feel like a small celebration.

And the best part? It welcomes your own personal touch.

The Humble, Heroic Casserole

Let’s talk about the casserole itself. What exactly is it?

At its heart, a casserole is a beautiful, efficient idea. It’s a complete meal baked together in one dish. You typically have a protein, some vegetables, a starchy element, and a sauce that brings it all into creamy, cozy harmony.

Many classic recipes, from decades past, relied on canned soup for that creamy binding.

This version takes a different, fresher path.

We make a real, from-scratch cheese sauce. It’s silky and decadent, clinging to every noodle and piece of chicken. It feels homemade in the very best way.

This approach gives you control, and a much deeper, more satisfying flavor.

Ingredients Needed for the Recipe

Gathering everything first makes the process smooth and enjoyable. Here’s what you’ll need.

• Egg Noodles (12 ounces): The classic, comforting base. Their ruffled edges are perfect for catching all that creamy sauce.
• Diced Cooked Chicken (2 cups): The star protein. This is a brilliant way to use leftovers from a roast chicken or last night’s grilled breasts.
• Butter (3 tablespoons total): For sautéing and building our sauce. It adds a foundational richness.
• Sliced Mushrooms (10 ounces): They bring an earthy, savory depth and a wonderful meaty texture to the mix.
• Minced Garlic (2 tablespoons): The essential flavor booster. It perfumes the entire vegetable sauté.
• Fresh Spinach (3 cups): It wilts down beautifully, adding pops of color and a mild, fresh flavor that balances the richness.
• Scallions (2, diced): They go in the sauce, providing a subtle, aromatic onion note.
• All-Purpose Flour (2 tablespoons): This combines with butter to make a roux, which thickens our sauce perfectly.
• Chicken Broth (3 cups): The liquid foundation of the sauce, adding savory depth.
• Heavy Cream (1 cup): This is the key to the luxurious, creamy texture we’re after.
• Shredded Asiago Cheese (2 cups): I love Asiago for its sharp, nutty character. It makes the sauce incredibly flavorful.
• Kosher Salt & Black Pepper: For seasoning. Always taste as you go.

How to Make Creamy Chicken, Spinach and Mushroom Casserole?

The magic happens in a few simple stages. It’s really about building layers of flavor, one pan at a time.

Step 1: Prep and Preheat

Start by preheating your oven to 350°F (175°C). This gives it time to reach the perfect temperature.

Then, bring a large pot of salted water to a boil for your egg noodles. We’ll cook them soon.

Getting these two things going first sets you up for a seamless cooking flow.

Step 2: Cook the Noodles

Cook the egg noodles according to the package directions, but with one small, crucial tip.

Stop cooking when they are just al dente. This means they should still have a slight bite to them.

They will soften further as they bake in the oven. If you cook them completely now, they might become mushy later. Drain them and set them aside.

Step 3: Sauté the Vegetables and Chicken

While the noodles cook, take a large sauté pan. Melt one tablespoon of butter over medium heat.

Add the sliced mushrooms and minced garlic. You’ll hear a lovely sizzle. Sauté this for about two minutes, just until the mushrooms begin to soften and release their aroma.

Now, add the massive-looking pile of fresh spinach and the diced cooked chicken. Gently stir everything together. It’s satisfying to watch the vibrant spinach wilt down into the mix within a minute or so. Once the spinach is wilted and the chicken is heated through, remove the pan from the heat.

Step 4: Create the Creamy Sauce

This is where the dish becomes truly special. In a medium saucepan, melt the remaining two tablespoons of butter.

Add the diced scallions and stir for about a minute, just until they’re fragrant.

Sprinkle in the flour and whisk constantly for another minute. You’ve just made a roux, a simple paste that will thicken the sauce.

Slowly pour in the chicken broth while whisking continuously. This prevents any lumps from forming.

Now, add the shredded Asiago cheese, salt, and pepper. Keep whisking over medium heat until the cheese is fully melted and the sauce is smooth.

In your small saucepan, gently warm the heavy cream. You don’t want it to boil, just to take the chill off. Stir the warm cream into the cheese sauce. Taste it. Adjust the seasoning if needed. It should be rich, cheesy, and perfectly smooth.

Step 5: Combine and Bake

In a large bowl, or right in your sauté pan if it’s big enough, combine the drained egg noodles, the vegetable and chicken mixture, and all of that glorious creamy sauce.

Gently fold everything together until it’s evenly coated. It will look and smell amazing already.

Transfer this mixture to a greased 9×13 inch casserole dish. Spread it out into an even layer.

Place it in your preheated oven and bake for 30 minutes. You’re waiting for it to become hot and bubbly all the way through, with perhaps just a few golden spots on top.

Let it rest for 5 minutes after baking. This helps it set beautifully for serving.

Choosing Your Chicken: Shortcuts and Secrets

This recipe is wonderfully flexible when it comes to the chicken. Don’t have leftover roasted chicken? No problem at all.

A store-bought rotisserie chicken is a fantastic shortcut. Just shred or dice the meat.

You can also find pre-cooked, diced chicken in the refrigerated meat section of most grocery stores.

If you prefer to cook it fresh, simply dice two raw chicken breasts.

Sauté them in a little olive oil in your pan before you cook the mushrooms, until they are no longer pink. Then set them aside and proceed with the recipe.

Any of these methods works perfectly. The goal is simply to have cooked, ready-to-use chicken.

Serving and Enjoying Your Creation

This casserole is a complete meal in a dish. It truly doesn’t need much alongside it.

A simple green salad with a tangy vinaigrette provides a refreshing, crisp contrast to the creamy richness.

Some crusty bread is also wonderful, for soaking up every last bit of sauce on the plate.

Serve it directly from the dish at the table. Let everyone see the steam rise and hear the gentle bubble.

It’s food that invites people to gather, to share, and to relax. That, after all, is the true spirit of a casserole.

It’s food that takes care of you.

Tips

• Cheese Choices: While Asiago is my favorite, feel free to experiment. A good sharp cheddar, fontina, gruyère, or a mix will also create a delicious, melty sauce.
• Make-Ahead Magic: This is a fantastic make-ahead meal. Assemble the entire casserole, cover it tightly, and refrigerate for up to 24 hours. When ready, you may need to add 5-10 minutes to the baking time since it will be going in cold.
• Freezing for Later: After baking and cooling, portion the casserole into airtight containers and freeze for up to 3 months. It reheats beautifully for a quick future dinner.
• The Reheating Trick: When reheating leftovers from the fridge or freezer, add a small splash of milk, broth, or water before warming. This helps to restore the creamy consistency and prevents dryness.
• Pasta Alternatives: Egg noodles are classic, but other short pastas like penne, fusilli, or cavatappi work wonderfully. They hold the sauce in their nooks and crannies.

Why This Recipe Works So Well

This recipe succeeds because it balances simplicity with real culinary technique. It doesn’t cut corners on flavor.

Making a proper roux-based sauce might sound like a small step, but it makes all the difference. It gives you a superior texture and a cleaner, richer taste.

Using fresh vegetables, like spinach and mushrooms, adds brightness and texture that canned versions simply can’t match.

Finally, this dish understands the value of your time. The active preparation is straightforward and relatively quick.

The oven does the rest of the work, filling your home with an irresistible aroma. It’s a recipe that respects both the food and the cook.

That, I’ve learned, is the secret to a great casserole. It’s practical, yes. But it’s also deeply, deliciously satisfying.

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Creamy Chicken, Spinach and Mushroom Casserole Recipe

Author: Sarah Onida Cooking Method: Baking Cuisine: American Courses: Dinner

Difficulty: easy Prep Time 20 mins Cook Time 30 mins Rest Time 5 mins Total Time 55 mins

Cooking Temp: 175  C Servings: 6 Estimated Cost: $ 15 Calories: 480

Best Season: Fall, Winter

Description

This Creamy Chicken, Spinach & Mushroom Casserole makes for the perfect weeknight meal. It’s rich, comforting, and easy to prepare ahead of time—ideal for busy evenings. With tender egg noodles, sautéed mushrooms, fresh spinach, and shredded chicken all wrapped in a velvety cheese sauce, this dish is sure to become a family favorite.

ingredients

Scale

1/2x 1x 2x 3x

For the Casserole

• 12 ounces egg noodles (uncooked)
• 2 cups diced cooked chicken breasts (rotisserie or leftover chicken works well)
• 1 tablespoon butter
• 10 ounces sliced mushrooms (cremini or white button)
• 2 tablespoons minced garlic
• 3 cups fresh spinach (packed)

For the Sauce

• 2 tablespoons butter
• 2 scallions (diced)
• 2 tablespoons all purpose flour
• 3 cups chicken broth (low sodium preferred)
• 1 cup heavy cream
• 2 cups shredded asiago cheese (or other soft/semi-soft cheese like mozzarella or fontina)
• ½ teaspoon kosher salt
• ¼ teaspoon black pepper

Instructions

For the Casserole

1. Preheat oven to 350°F (175°C).
2. Cook egg noodles according to package directions until al dente. Drain and set aside.
3. In a large sauté pan, melt 1 tablespoon butter over medium heat. Add mushrooms and garlic; sauté for 2 minutes until mushrooms begin to soften.
4. Add spinach and cooked chicken. Stir until spinach wilts and everything is heated through. Remove from heat.

For the Sauce

1. In a small saucepan, warm the heavy cream over medium heat (do not boil). Set aside.
2. In a medium saucepan, melt 2 tablespoons butter over medium heat. Add diced scallions and cook for 1 minute.
3. Whisk in flour to form a roux. Cook for 1 minute, stirring constantly.
4. Gradually whisk in chicken broth. Bring to a gentle simmer and cook until slightly thickened, about 3–4 minutes.
5. Stir in shredded Asiago cheese, salt, and pepper. Continue stirring until cheese is fully melted and sauce is smooth.
6. Remove from heat and stir in the warmed heavy cream until fully incorporated.

Assembly & Baking

1. In a large mixing bowl, combine the cooked egg noodles, chicken-spinach-mushroom mixture, and prepared sauce. Mix gently until evenly coated.
2. Transfer mixture to a greased 9x13-inch casserole dish.
3. Bake uncovered for 30 minutes, or until hot and bubbly with light golden edges.
4. Let rest for 5 minutes before serving.

Nutrition Facts

Servings 6

Serving Size 1 cup

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Amount Per Serving

Calories 480kcal

% Daily Value *

Total Fat 27g42%

Saturated Fat 15g75%

Trans Fat 0.5g

Cholesterol 125mg42%

Sodium 890mg38%

Potassium 620mg18%

Total Carbohydrate 32g11%

Dietary Fiber 2g8%

Sugars 4g

Protein 28g57%

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Calcium 25 mg

Iron 10 mg

* Percent Daily Values are based on a 2,000 calorie diet. Your daily value may be higher or lower depending on your calorie needs.

Note

• Make ahead: Assemble the casserole up to 1 day in advance. Cover and refrigerate. Bake 35–40 minutes if cold.
• Freezing tip: Freeze unbaked casserole for up to 3 months. Thaw overnight in fridge before baking.
• Reheating: Add a splash of milk or broth when reheating to restore creaminess.
• Cheese swap: Try Gruyère, Gouda, or sharp cheddar for different flavor profiles.

Keywords: chicken casserole, creamy chicken spinach mushroom casserole, easy weeknight dinner, make-ahead casserole, comfort food