Creamy Chicken Tetrazzini with Parmesan (Print version)

A cozy chicken tetrazzini pasta bake with spaghetti, mushrooms, Parmesan cream sauce, and a crisp golden topping.

# Ingredients:

For the pasta and chicken

01 - 12 oz (340 g) spaghetti
02 - 3 cups (420 g) cooked shredded chicken
03 - 1 cup (120 g) frozen peas, optional
04 - 1 tablespoon butter, for the baking dish

For the Parmesan sauce

05 - 4 tablespoons (56 g) unsalted butter
06 - 8 oz (225 g) cremini or button mushrooms, sliced
07 - 1 small yellow onion, finely diced
08 - 3 cloves garlic, minced
09 - 1/4 cup (32 g) all-purpose flour
10 - 2 cups (480 ml) low-sodium chicken broth
11 - 1 cup (240 ml) whole milk
12 - 1 cup (240 ml) heavy cream
13 - 1 teaspoon kosher salt, plus more for pasta water
14 - 1/2 teaspoon black pepper
15 - 1/4 teaspoon dried thyme
16 - 1 cup (90 g) freshly grated Parmesan cheese

For the topping

17 - 3/4 cup (45 g) panko breadcrumbs
18 - 2 tablespoons (28 g) unsalted butter, melted
19 - 1/3 cup (30 g) freshly grated Parmesan cheese
20 - 2 tablespoons chopped fresh parsley

# Instructions:

01 - Heat the oven to 375 F. Butter a 9x13-inch baking dish. Boil the spaghetti in salted water until 1 minute shy of al dente, then drain well.
02 - Melt 4 tablespoons butter in a large deep skillet or Dutch oven over medium-high heat. Add mushrooms and cook for 6-8 minutes, stirring often, until their moisture cooks off and the edges begin to brown.
03 - Add the onion and cook for 3 minutes until softened. Stir in the garlic and cook for 30 seconds, just until fragrant.
04 - Sprinkle in the flour and stir for 1 minute. Slowly whisk in the chicken broth, then the milk and cream. Add salt, pepper, and thyme. Simmer for 4-6 minutes until the sauce lightly coats a spoon.
05 - Remove the skillet from the heat. Stir in 1 cup Parmesan until melted and smooth. Taste and adjust salt if needed.
06 - Fold in the cooked spaghetti, shredded chicken, and peas if using. Spread the mixture evenly into the prepared baking dish.
07 - Mix panko, melted butter, and 1/3 cup Parmesan in a small bowl. Sprinkle over the casserole. Bake for 22-28 minutes until bubbling at the edges and golden on top. Rest 5-10 minutes, then finish with parsley.

# Good to know:

01 - Best baked in a 9x13-inch dish so the center heats evenly.
02 - The sauce should look loose before baking because pasta absorbs moisture in the oven.
03 - Rest for 5-10 minutes before serving for cleaner, creamier scoops.