Recipe for Chicken Tetrazzini Bake: Cheesy Pasta Casserole with Mushroom Depth

This chicken tetrazzini bake transforms simple ingredients into a creamy, cheesy casserole with rich mushroom flavor. I developed this recipe after testing countless variations to achieve the perfect balance of textures and tastes.

Tender pasta, shredded chicken, and earthy mushrooms come together under a golden, bubbling cheese topping. The sauce is velvety without being heavy, thanks to a careful balance of cream, broth, and Parmesan.

Baking at high heat creates a perfectly browned crust while keeping the interior moist and flavorful. It’s a dish that looks impressive but requires minimal effort for maximum payoff.

Serve it straight from the oven for a comforting meal that’s ideal for family dinners or potlucks. This one stays in my regular rotation for good reason.

Ingredients for Recipe for Chicken Tetrazzini Bake

Creamy, cheesy, and packed with mushroom depth—these ingredients build a restaurant-worthy bake at home.

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The chicken is the foundation here. Boneless, skinless breasts stay tender when shredded, but thighs work too if you prefer darker meat. Costco has excellent pre-trimmed breasts in bulk. For mushrooms, cremini (baby bellas) offer the deepest flavor, but white button mushrooms are a fine substitute. Always buy Parmesan in a wedge—pre-grated contains anti-caking agents that make the sauce grainy.

No white wine? Substitute chicken broth with 1 tsp lemon juice. Dried mushrooms rehydrated in warm water can replace fresh if needed (reserve the soaking liquid). For a lighter version, half-and-half works at a 1:1 ratio but the sauce won’t be as rich. The Dijon mustard is subtle but essential—yellow mustard lacks the complexity. Use whole wheat fettuccine for extra fiber if desired.

Assemble the casserole up to 24 hours ahead and refrigerate. Bake straight from the fridge, adding 10-15 minutes to the time. Leftovers keep 4-5 days refrigerated or freeze for 3 months. Reheat covered with foil to prevent drying (a splash of broth helps revive it).

Step-by-Step Instructions for Chicken Tetrazzini Bake

Here’s the method. Straightforward, tested, works every time.

Step 1: Cook Pasta and Shred Chicken

Bring a large pot of salted water to a rolling boil. Add the 12 oz fettuccine pasta and cook for 2 minutes less than package directions for al dente. The pasta will finish cooking in the oven, preventing it from turning mushy in the final dish.

Drain the pasta and rinse briefly under cold water to stop the cooking process. Set aside. Meanwhile, poach or bake the 1.5 lb boneless skinless chicken breasts until fully cooked through to 165°F. Once cool enough to handle, shred the chicken into bite-sized pieces using two forks.

Step 2: Sauté Aromatics and Mushrooms

In a large skillet over medium heat, melt ¼ cup of the unsalted butter. Add the finely diced yellow onion and cook for 3-4 minutes until translucent and softened. Stir in the sliced cremini mushrooms and cook for another 5-6 minutes until they release their moisture and turn golden brown.

Add the minced garlic cloves and cook for 30 seconds until fragrant. Deglaze the pan with the 0.5 cup dry white wine, scraping up any browned bits from the bottom. Cook for 2 minutes until the liquid reduces by half. This builds a deep, savory base for your sauce.

Step 3: Make the Creamy Roux-Based Sauce

In the same skillet, melt the remaining ¼ cup unsalted butter over medium heat. Whisk in the 0.33 cup all-purpose flour to form a smooth roux. Cook for 1-2 minutes, stirring constantly, until the mixture turns a light golden color—this removes the raw flour taste.

Gradually whisk in the 2 cups chicken broth and 1.5 cups heavy cream, ensuring no lumps form. Stir in the 1 tbsp Dijon mustard and 1.5 tsp kosher salt. Simmer for 3-4 minutes until the sauce thickens enough to coat the back of a spoon. Remove from heat and stir in ½ cup of the parmesan cheese until melted.

Step 4: Assemble and Bake the Tetrazzini

In a large bowl, combine the cooked fettuccine, shredded chicken, mushroom mixture, and creamy sauce. Toss everything together until the pasta is evenly coated. Transfer the mixture to a greased 9×13-inch baking dish and spread it into an even layer.

Sprinkle the remaining ½ cup parmesan cheese and all 2 cups shredded cheddar cheese evenly over the top. Bake in a preheated 375°F oven for 20-25 minutes until the cheese is bubbly and golden brown and the edges are slightly crispy. For extra browning, broil for 1-2 minutes at the end, watching closely.

Step 5: Rest and Serve

Remove the tetrazzini bake from the oven and let it rest for 5-10 minutes. This allows the sauce to thicken slightly and makes it easier to serve neat portions. The internal temperature should register at least 165°F in the center to ensure it’s fully heated through.

Garnish with additional freshly ground black pepper if desired. Serve hot, with each portion showcasing the creamy sauce, tender chicken, and rich mushroom flavor throughout. The top should have a beautiful golden cheese crust with the pasta underneath perfectly tender.

Common Mistakes When Making This Recipe

Overcooking the Pasta

Cook your 12 oz fettuccine for 2 minutes less than package directions. I learned this the hard way—overcooked pasta turns to mush during baking. Trust me, al dente is your friend here. 💡

Skipping the Roux

Don’t rush the roux step with your ¼ cup butter and ⅓ cup flour. Cook it to a light golden color to remove the raw flour taste. This builds the sauce’s rich foundation.

Underseasoning the Sauce

Taste as you go with the 1.5 tsp salt and ½ tsp pepper. The cheese and cream can mute flavors, so adjust before assembling. I always add an extra pinch of salt to balance the richness.

Skipping the Rest

Let your tetrazzini rest for 5-10 minutes after baking. This lets the sauce thicken and makes serving cleaner. Cutting too soon leads to a runny, messy dish.

Using Pre-Grated Cheese

Always grate your own Parmesan and cheddar. Pre-grated contains anti-caking agents that make the sauce grainy. Freshly grated melts beautifully and creates that perfect golden crust. ✨

Overcrowding the Pan

Sauté your 8 oz mushrooms in batches if needed. Overcrowding steams them instead of browning, which dulls their earthy flavor. A golden sear adds depth to your dish.

Frequently Asked Questions