Chicken Tetrazzini Recipe

Preheat and cook pasta

Preheat oven to 375°F (190°C). Bring a large pot of salted water to a boil. Add the pasta and cook until al dente according to package instructions (usually 8–10 minutes). Reserve 1 cup of pasta cooking water, then drain the pasta and set aside.

Prepare chicken

If not already roasted, roast or sear 1–1.5 lb chicken breast or thighs: season with salt and pepper, roast at 400°F (200°C) for 20–25 minutes until internal temperature reaches 165°F (74°C). Let rest, then shred or dice into roughly 1/2-inch pieces. Use 3 cups cooked chicken for the casserole.

Toss the drained pasta with 1 tablespoon olive oil to prevent sticking and set aside until ready to combine.

In a large skillet over medium-high heat, add 1 tablespoon olive oil. Add the sliced mushrooms and sauté until they release their moisture and begin to brown, about 5–6 minutes. Season lightly with 1/4 tsp salt and 1/4 tsp pepper.

Add the halved cherry tomatoes to the skillet and cook 2–3 minutes until they soften but keep shape. Remove mushrooms and tomatoes from heat and set aside.

Stir in the sliced basil (from basil in oil) with the cooked mushrooms and tomatoes so the basil warms and blends with the vegetables.

Make a roux

In a medium saucepan over medium heat, melt 4 tablespoons butter. Add the minced garlic and sauté 30–45 seconds until fragrant but not browned. Sprinkle in 2 tablespoons flour and whisk continuously for 1–2 minutes to cook the flour (do not brown).

Finish sauce

Slowly whisk in 1 cup whole milk and 1 cup heavy cream, bringing the mixture to a gentle simmer. Continue to whisk until sauce thickens slightly, about 3–5 minutes. Remove from heat and stir in 1 cup grated Parmesan until melted and smooth. Season with 1 teaspoon salt, 1 teaspoon freshly ground black pepper, and a pinch of nutmeg if using. If sauce is too thick, whisk in up to 1/2 cup reserved pasta water to reach a saucy consistency.

Assemble casserole

In a large mixing bowl or directly in a 9x13-inch baking dish, combine the cooked pasta, shredded chicken, sautéed mushrooms and tomatoes with warmed basil, and the Parmesan Alfredo sauce. Mix gently to coat everything evenly. If the mixture seems dry, add a few tablespoons of reserved pasta water.

Prepare topping

In a small bowl, combine 3 tablespoons breadcrumbs, 2 tablespoons grated Parmesan (topping), and 1 tablespoon melted butter. Sprinkle this mixture evenly over the top of the assembled casserole. Optionally sprinkle an additional 2–3 tablespoons grated Parmesan across the surface for extra crust.

Bake

Bake in the preheated 375°F (190°C) oven for 18–22 minutes, until the top is golden and the casserole is bubbling around the edges. For a more browned top, place under the broiler for 1–2 minutes—watch closely to avoid burning.

Remove from oven and let rest 5 minutes. Garnish with chopped fresh parsley and serve hot.