Creamy Chicken Tetrazzini Casserole in 45 Minutes
This chicken tetrazzini casserole is a creamy, garlicky pasta bake with tender chicken, mushrooms, and a golden breadcrumb top. It’s the kind of dinner that feels special without a whole afternoon in the kitchen.
It’s a weeknight-friendly version of the classic, ready in about 45 minutes. You’ll want to put this on repeat.
Why This Casserole Works
The sauce is what makes it. Butter, flour, broth, and milk build an easy white sauce that turns silky with Greek yogurt and Parmesan. It clings to every strand of spaghetti without getting heavy.
I also love that the chicken stays moist inside the bake while the panko on top gets crisp. You get creamy and crunchy in every bite, and the little pop of thyme pulls it all together.
Ingredients
- 12 oz spaghetti: use thin spaghetti or linguine if you prefer.
- 2 tbsp unsalted butter: for the mushroom base.
- 8 oz cremini mushrooms, sliced: white button mushrooms work too.
- 1 small yellow onion, diced fine: about 1 cup.
- 3 garlic cloves, minced: fresh, not jarred, for the best flavor.
- 1/4 cup all-purpose flour: thickens the sauce.
- 1 cup low-sodium chicken broth: or vegetable broth.
- 1 cup whole milk: 2% will work but the sauce won’t be as rich.
- 1/2 cup dry white wine: replace with more broth if you prefer no alcohol.
- 1/2 cup plain Greek yogurt: full-fat gives the smoothest texture.
- 1 cup shredded cooked chicken: a rotisserie bird or leftover roast chicken is perfect.
- 1/2 cup freshly grated Parmesan cheese: plus a little more for serving.
- 3/4 tsp kosher salt: adjust if your broth is salted.
- 1/4 tsp black pepper
- 1/2 tsp dried thyme: fresh thyme leaves are lovely too, just double the amount.
- 1/2 cup panko breadcrumbs: for the crisp topping.
- 1 tbsp olive oil: helps the topping brown.
Variations / Substitutions
- Turkey instead of chicken: leftover roasted turkey is a natural stand-in, especially after the holidays.
- No wine: simply increase the broth to 1 1/2 cups total. The sauce will still be wonderful.
- Add a veggie: stir 1 cup of frozen peas into the sauce just before adding the chicken.
- Gluten-free: use your favorite gluten-free spaghetti and replace the flour with a 1:1 gluten-free blend.
If you love a creamy pasta bake, try our One-Pot Creamy Chicken and Bacon Pasta next.
How to Make Chicken Tetrazzini Casserole
Step 1: Cook the Pasta
Bring a large pot of salted water to a boil. Add the 12 oz of spaghetti and cook until just al dente, about 1 minute less than the package says (usually 7 to 8 minutes). The pasta will keep cooking in the oven, so you want a little bite left. Drain and set aside. Reserve about 1/2 cup of the starchy pasta water before you drain, you might need it later.
Step 2: Sauté the Mushrooms
While the pasta cooks, melt the 2 tbsp of butter in a large skillet over medium-high heat. Add the sliced mushrooms and diced onion. Cook, stirring occasionally, for about 6 to 8 minutes until the mushrooms release their liquid and turn deeply golden. The edges should look crisp, not steamed. Stir in the minced garlic and 1/2 tsp dried thyme and let it go for another 30 seconds until you can smell the garlic.
Step 3: Build the Creamy Sauce
Sprinkle the 1/4 cup of flour over the mushroom mixture and cook, stirring constantly, for 1 minute. This cooks out the raw flour taste. Slowly pour in the 1 cup of chicken broth, the 1 cup of whole milk, and the 1/2 cup of white wine, whisking as you go so no lumps form. Bring the sauce to a gentle simmer and let it bubble for about 3 to 4 minutes, whisking now and then, until it coats the back of a spoon.
Turn off the heat. Stir in the 1/2 cup of Greek yogurt, the 1/2 cup of Parmesan, the shredded chicken, 3/4 tsp salt, and 1/4 tsp pepper. The sauce should be creamy and thick. Taste it and adjust the salt if needed.
Step 4: Assemble the Casserole
Preheat your oven to 375°F (190°C). Add the drained spaghetti to the skillet with the sauce. Toss everything together right in the skillet, adding a splash of the reserved pasta water if the sauce feels too tight. You want every strand coated evenly.
Scrape the saucy pasta into a 9×13-inch baking dish (or a similar 3-quart casserole). Spread it out so the top is even.
Step 5: Top and Bake Until Golden
In a small bowl, toss the 1/2 cup of panko breadcrumbs with the 1 tbsp of olive oil and a tiny pinch of salt. Sprinkle the mixture across the surface of the casserole. Bake for 20 to 22 minutes until the sauce is bubbling at the edges. To really crisp the top, switch the oven to broil and watch it closely for 1 to 2 minutes until the panko turns deep golden brown.
Scoop generous portions onto plates and serve while it’s hot and bubbly.
Tips for the Best Tetrazzini
- Undercook the pasta slightly. It will continue to absorb liquid in the oven, so pulling it a minute early keeps the texture just right.
- Freshly grate the Parmesan. Pre-shredded cheese often has anti-caking agents that keep it from melting into the sauce as smoothly.
- Buy pre-sliced mushrooms if you want to save a few minutes of prep. No one will notice the difference in a baked dish.
- For an even crunchier topping, replace the olive oil with 1 tablespoon of melted butter when mixing the panko.
- Let the casserole rest for 5 minutes after baking. It firms up a little and is much easier to scoop.
Bake times by dish material:
| Dish material | Bake time at 375°F | Notes |
|---|---|---|
| Ceramic | 22–25 minutes | Holds heat evenly, may need the full 25. |
| Metal | 20–22 minutes | Conductive and quick, check at 20. |
| Glass (Pyrex) | 23–25 minutes | Heats slower, similar to ceramic. |
Keeping Leftovers Fresh
- Refrigerate: store leftover casserole in an airtight container for up to 3 days.
- Reheating: warm individual portions in the microwave or cover the whole dish with foil and reheat at 350°F for about 15 minutes.
- Serve cold: this one is best served hot, the texture of the sauce tightens when chilled.
What to Serve with Chicken Tetrazzini
A lemony arugula salad cuts through the richness beautifully. Steamed green beans with a little lemon zest are another bright, simple side. If you want something heartier, roasted broccoli tossed with olive oil and garlic roasts at the same temperature as the casserole, just pop it in on a lower rack for the last 15 minutes.
Frequently Asked Questions
Can I assemble this casserole the night before?
Yes. Make the recipe through Step 4, cover tightly, and refrigerate. The next day, top with the panko mixture and bake, adding 5 to 10 minutes since it starts cold.
What can I use instead of panko breadcrumbs?
Regular dried breadcrumbs or crushed Ritz crackers both work, though they give a slightly less airy crunch.
Can I use a different pasta shape?
Egg noodles, fettuccine, or even penne are all fine. Just cook them to the same al dente point so they hold up in the bake.
Do I have to broil the top?
No, the casserole is fully cooked after baking. Broiling just gives you that golden, crisp topping. If your broiler runs hot or you prefer a softer top, skip it.
Chicken Tetrazzini Casserole Recipe
Ingredients
Method
- Cook spaghetti in salted boiling water until just al dente, about 7 to 8 minutes. Drain and reserve 1/2 cup pasta water.
- Melt butter in a large skillet over medium-high heat. Sauté mushrooms and onion for 6 to 8 minutes until golden. Stir in garlic and thyme, cook 30 seconds.
- Add flour and cook 1 minute. Gradually whisk in broth, milk, and wine. Simmer for 3 to 4 minutes until slightly thickened. Off heat, stir in yogurt, Parmesan, chicken, salt, and pepper.
- Preheat oven to 375°F (190°C). Toss spaghetti with the sauce, adding a splash of pasta water if needed. Transfer to a 9×13-inch baking dish.
- Mix panko with olive oil and a pinch of salt. Sprinkle over the casserole. Bake 20 to 22 minutes until bubbling, then broil 1 to 2 minutes for a golden top. Scoop and serve hot.
