Easy Chicken Tetrazzini

Name: Easy Chicken Tetrazzini
Total Time: 1 hour 5 minutes (Prep: 20 mins, Cook: 45 mins)
Servings: 8
Difficulty: Easy
Dietary Tags: Comfort Food, Family-Friendly, Make-Ahead Casserole

Introduction

Gather your family around the table for a warm, nostalgic embrace with this Easy Chicken Tetrazzini. This classic American casserole is the epitome of comfort food: tender pasta and shredded chicken bathed in a luxuriously creamy, Parmesan-infused sauce, punctuated with savory mushrooms and peas, all baked under a golden, buttery breadcrumb topping. Far from the bland, gloppy versions of the past, this recipe delivers deep flavor with a streamlined process, using a simple roux-based sauce that comes together in one pot. Perfect for feeding a crowd, utilizing leftover holiday turkey or rotisserie chicken, or simply delivering a hearty, satisfying weeknight meal, this Tetrazzini is creamy, dreamy, and guaranteed to become a beloved staple in your dinner rotation.

Equipment Needed

Large pot for boiling pasta
Large, deep skillet or Dutch oven
9×13 inch baking dish
Colander
Whisk
Measuring cups and spoons
Cutting board and chef’s knife
Small bowl for topping

Ingredients

For the Pasta & Chicken:

12 oz (340g) dried spaghetti or linguine, broken in half
4 cups cooked chicken, shredded or cubed (from 1 rotisserie chicken or about 1.5 lbs of cooked breasts/thighs)
1 cup frozen peas, thawed (no need to cook)

For the Creamy Sauce:

4 tablespoons (½ stick / 56g) unsalted butter
8 oz (225g) white mushrooms, cleaned and sliced
1 medium yellow onion, finely diced
3 cloves garlic, minced
⅓ cup (42g) all-purpose flour
4 cups (960ml) low-sodium chicken broth
1 cup (240ml) heavy cream or half-and-half
1 cup (100g) grated Parmesan cheese, divided
2 teaspoons fresh thyme leaves (or ½ teaspoon dried thyme)
½ teaspoon freshly grated nutmeg
Salt and freshly ground black pepper to taste

For the Buttery Topping:

1 cup Panko breadcrumbs
¼ cup grated Parmesan cheese
2 tablespoons unsalted butter, melted
2 tablespoons chopped fresh parsley

Instructions

Phase 1: Cook the Pasta & Prep Ingredients

Time: 15 minutes | Intensity: Medium

Boil Pasta: Preheat your oven to 375°F (190°C). Bring a large pot of salted water to a boil. Cook the broken spaghetti according to package directions for al dente (it will finish cooking in the oven). Drain and set aside.
Prep Proteins & Veg: While the pasta cooks, shred your cooked chicken and set aside. Ensure the peas are thawed.

Phase 2: Build the Cream Sauce (The Heart of the Dish)

Time: 20 minutes | Intensity: Medium-High

Sauté Mushrooms & Onion: In your large skillet or Dutch oven, melt the 4 tablespoons of butter over medium-high heat. Add the sliced mushrooms and diced onion. Cook, stirring occasionally, for 6-8 minutes, until the mushrooms have released their liquid and are browned, and the onion is soft.
Add Garlic & Flour: Add the minced garlic and cook for 1 minute until fragrant. Sprinkle the flour over the mushroom mixture. Cook, stirring constantly, for 1-2 minutes to cook off the raw flour taste. This creates your roux.
Whisk in Liquids: Gradually pour in the chicken broth while whisking constantly to prevent lumps. Then whisk in the heavy cream. Bring the mixture to a simmer, continuing to whisk. It will thicken noticeably within 3-5 minutes.
Season & Cheese: Reduce heat to low. Stir in ¾ cup of the grated Parmesan cheese, thyme, nutmeg, and a generous amount of black pepper. Taste the sauce—it should be well-seasoned. Add salt carefully (the broth and Parmesan add salt). Remove from heat.

Phase 3: Assemble the Casserole

Time: 10 minutes | Intensity: Low

Combine: To the pot with the creamy sauce, add the drained cooked pasta, shredded chicken, and thawed peas. Gently fold everything together with a large spoon or spatula until every component is evenly coated in the sauce.
Transfer to Dish: Pour the entire mixture into your ungreased 9×13 inch baking dish and spread it into an even layer.

Phase 4: Add the Crunchy Topping & Bake

Time: 25 minutes | Intensity: Low (Oven does the work)

Make Topping: In a small bowl, combine the Panko breadcrumbs, the remaining ¼ cup of Parmesan, melted butter, and parsley. Mix with a fork until the crumbs are evenly moistened.
Top & Bake: Sprinkle the breadcrumb mixture evenly over the top of the casserole. Bake in the preheated oven, uncovered, for 20-25 minutes, or until the topping is golden brown and the sauce is bubbling around the edges.

Phase 5: Rest and Serve