Ingredients
For the Sauce and Filling
- 6 tablespoons unsalted butter, divided
- 1 pound cremini mushrooms, sliced
- 1 cup small chopped shallots or yellow onion
- 2 cloves garlic, finely chopped
- 1 teaspoon fresh thyme leaves, chopped
- 1/3 cup all purpose flour
- 2 cups chicken broth or stock
- 2 cups whole milk
- 1 1/2 cups heavy cream
- 2-3 tablespoons dry sherry
- 1/8 teaspoon ground nutmeg
- 3/4 cup grated Parmigiano Reggiano
- 3/4 cup frozen peas
- 3 cups shredded cooked turkey breast
- 1/4 cup chopped Italian parsley, plus additional for garnish
- 12 ounces dry linguine or spaghetti, snapped in half
- Kosher salt and freshly ground black pepper, to taste
For the Topping
- 1 tablespoon unsalted butter, melted
- 1/2 cup unseasoned Panko breadcrumbs
- 1/4 cup grated Parmigiano Reggiano
- 1/4 teaspoon freshly ground black pepper
Instructions
- Prep: Preheat the oven to 400°F (200°C). Butter a 4.8-quart (13×9 inch) casserole dish to prevent sticking.
- Cook Pasta: In a large pot of salted boiling water, cook the linguine or spaghetti until just al dente. Drain and set aside.
- Sauté Mushrooms: Melt 2 tablespoons of butter in a large, heavy-bottomed pot over medium-high heat. Add the sliced mushrooms, 1/2 teaspoon salt, and 1/4 teaspoon pepper. Cook until the mushrooms release their liquids and most of it has evaporated, about 5 minutes.
- Add Aromatics: Stir in the chopped shallots or onions and cook for 3 to 4 minutes until the mushrooms start to brown. Add finely chopped garlic and thyme leaves; cook for 1 minute until fragrant. Remove this mixture from the pan and set aside.
- Make the Sauce: In the now-empty pan, melt 4 tablespoons of butter. Stir in the flour and cook for 1 to 2 minutes to form a roux. Gradually whisk in chicken broth, whole milk, heavy cream, dry sherry, ground nutmeg, 1 teaspoon kosher salt, and 1/2 teaspoon black pepper. Continue whisking for about 5 minutes until the sauce thickens, becomes smooth, and coats the back of a spoon.
- Finish Sauce: Whisk in 3/4 cup grated Parmigiano Reggiano until fully combined. Remove from heat and fold in the sautéed mushroom mixture, frozen peas, shredded turkey breast, and chopped Italian parsley. Adjust seasoning with additional salt and pepper if needed.
- Assemble Casserole: Stir the cooked pasta into the sauce mixture until evenly coated. Pour everything into the prepared, buttered casserole dish.
- Prepare Topping: In a small bowl, combine the melted butter, Panko breadcrumbs, 1/4 cup grated Parmigiano Reggiano, and 1/4 teaspoon freshly ground black pepper. Sprinkle this breadcrumb topping evenly over the casserole.
- Bake: Place the casserole on a baking sheet and bake in the preheated oven for about 25 minutes, until the topping is golden brown and toasted and the sauce is bubbling. Around 15 minutes into baking, check the topping and if it’s browning too quickly, tent the casserole with foil to prevent burning.
- Rest and Serve: Allow the Tetrazzini to stand for a few minutes after baking to let the sauce thicken further. Garnish with additional chopped parsley and serve hot for a comforting and hearty meal.
Notes
- Use dry sherry sparingly and adjust according to your taste preference for subtle depth of flavor.
- Leftover cooked turkey works great in this recipe, making it a perfect way to use holiday or roasted turkey.
- Watch the breadcrumb topping closely during baking to avoid burning. Cover with foil if needed.
- Substitute gluten-free flour and pasta to make this recipe gluten-free, if desired.
- For a lighter version, use half-and-half instead of heavy cream, and reduce the butter in the topping.
- Frozen peas can be substituted with fresh peas when in season for a fresher taste.
- Prep Time: 20 minutes
- Cook Time: 1 hour
- Category: Casserole
- Method: Baking
- Cuisine: American
