This easy leftover turkey tetrazzini recipe turns about 3 cups of cooked turkey into a creamy, bubbling casserole that serves 6 to 8 people. Spaghetti, mushrooms, peas, Parmesan, mozzarella, and a simple homemade sauce come together in roughly 60 to 70 minutes, including 25 to 30 minutes in the oven.
Every forkful is rich and comforting without being difficult to make. The sauce is savory and creamy, the mushrooms add a hearty bite, the peas bring a little sweetness, and the baked cheese creates a golden top that makes this casserole especially inviting after a holiday meal.
Jump to RecipeWhy You’ll Love This Recipe
Leftover turkey tetrazzini is the kind of dinner that makes a full refrigerator feel manageable. Instead of serving the same turkey plate again, you fold the leftovers into tender pasta, a creamy mushroom sauce, sweet peas, and plenty of cheese.
The from-scratch sauce takes only a few extra minutes and gives the casserole a smooth, savory flavor. It begins with sautéed onion, mushrooms, and garlic, then becomes thick and spoon-coating with flour, broth, milk, sour cream, and cheese.
This recipe is also flexible enough for a relaxed weeknight. You can assemble it in the same dish you plan to bake, use turkey breast or dark meat, and put the casserole on the table with a simple salad or roasted vegetable.
If you enjoy classic comfort-food casseroles, you may also want to compare this recipe with our classic turkey tetrazzini guide for another serving idea.
Ingredients You’ll Need
The ingredient list is straightforward, with a few pantry staples doing most of the work. Break the spaghetti in half before boiling so it is easier to combine with the thick sauce and easier to serve from the baking dish.
- Spaghetti: Twelve ounces provides the hearty base for 6 to 8 servings.
- Cooked turkey: Use 3 cups of shredded or chopped refrigerated leftover turkey.
- Aromatics and mushrooms: Onion, sliced mushrooms, and garlic create a deeply savory foundation.
- Thickening ingredients: Flour, broth, and whole milk or half-and-half form the sauce.
- Cream and cheese: Sour cream, Parmesan, and mozzarella give the casserole its creamy texture and browned topping.
- Vegetables: Thawed frozen peas add color and a mild sweetness.
- Optional topping: Dry breadcrumbs or panko add a pleasant crisp finish beneath the cheese.
Have the peas thawed and the turkey cut before you start cooking. This keeps the sauce from sitting too long while you search for the remaining ingredients.
Building the Creamy Mushroom Sauce
The sauce is the heart of this casserole, so give the mushrooms enough time to release and cook off their liquid. Sauté the diced onion and sliced mushrooms in butter for 5 to 7 minutes, stirring occasionally, until the vegetables are soft and the skillet no longer looks watery.
Add the minced garlic only during the final 30 seconds of sautéing. Garlic can become bitter if it cooks too long, while this brief step is enough to release its aroma.
Sprinkle the flour directly over the vegetables and stir for 1 minute. This cooks away the raw flour taste and coats the vegetables before the liquid is added.
Whisk in the broth gradually, followed by the milk or half-and-half. Adding the liquid in stages helps prevent lumps, and a 3 to 5 minute simmer gives the sauce time to thicken.
Remove the pan from the heat before adding the sour cream and cheese. The gentler temperature helps the sour cream stay smooth and keeps the sauce creamy rather than grainy.
How to Make It Step-by-Step
Step 1: Heat the oven to 350°F and grease a 9-by-13-inch baking dish. Bring a large pot of salted water to a boil, add the spaghetti broken in half, and cook it 1 to 2 minutes less than the package directions so it remains just shy of al dente.
Step 2: Drain the spaghetti thoroughly, but do not rinse it. The slightly undercooked pasta will absorb some of the sauce as the casserole bakes, and skipping the rinse allows the sauce to cling to the noodles.
Step 3: Melt the butter in a large skillet or saucepan over medium heat. Add the diced onion and sliced mushrooms, then cook for 5 to 7 minutes until softened and most of the mushroom liquid has evaporated.
Step 4: Stir in the minced garlic and cook for about 30 seconds, just until fragrant. Sprinkle the flour over the vegetables and stir constantly for 1 minute so the flour coats the mixture evenly.
Step 5: Gradually whisk in the chicken or turkey broth, followed by the whole milk or half-and-half. Bring the sauce to a gentle simmer and cook for 3 to 5 minutes, stirring often, until it thickens enough to coat a spoon.
Step 6: Remove the skillet from the heat. Stir in the sour cream, kosher salt, black pepper, grated Parmesan, and 1/2 cup of the shredded mozzarella until the cheese melts into the warm sauce.
Step 7: Add the cooked turkey, thawed peas, and drained spaghetti to the skillet. Fold everything together carefully so the noodles stay intact and each strand gets coated with sauce.
Step 8: Transfer the mixture to the greased 9-by-13-inch baking dish and spread it into an even layer. Sprinkle the remaining 1/2 cup mozzarella over the top, then add the breadcrumbs or panko if you want extra crunch.
Step 9: Bake the casserole uncovered for 25 to 30 minutes, until the edges are bubbling and the top is lightly browned. Let it rest for 5 to 10 minutes before serving so the sauce can settle and each portion holds together.
Pro Tips for the Best Tetrazzini
- Protect the pasta texture: Fully cooked spaghetti can become soft or mushy in the oven, so stop boiling it slightly early.
- Watch the mushrooms: Do not rush the sauté. Cooking away excess liquid keeps the finished sauce from becoming thin.
- Choose the right dairy: Whole milk makes a creamy sauce, while half-and-half gives it a richer finish.
- Help dry turkey: If the leftover turkey is particularly lean or dry, use half-and-half and cover the casserole loosely with foil for the first 15 minutes of baking.
- Do not skip the resting time: Five to 10 minutes allows the sauce to thicken slightly, making the casserole easier to scoop.
- Check seasoning carefully: Broth, Parmesan, and leftover turkey can all contain salt, so taste the sauce before adding more than the listed teaspoon.
For a crispier top, use panko instead of fine breadcrumbs. Sprinkle it evenly over the mozzarella so every serving gets a small contrast of crunch.
Easy Variations and Serving Ideas
Spaghetti is traditional, but linguine, fettuccine, or a short pasta can be substituted. Keep the total pasta amount at 12 ounces and still cook it slightly under al dente before combining it with the sauce.
If mushrooms are not popular at your table, they can be omitted, although they provide important savory flavor. You can also add finely chopped celery or bell pepper if you have small amounts available and want more vegetable texture.
Some recipes use condensed cream of mushroom soup as a shortcut, but this version uses a simple flour-and-broth sauce for a fresher flavor and more control over the seasoning. A small amount of cream cheese can also be stirred into the warm sauce, though it is not needed for the creamy texture in this recipe.
Serve generous squares with a crisp green salad, steamed broccoli, or roasted vegetables. For another cozy side dish, pair dinner with these easy roasted potatoes, especially when you are feeding a crowd.
Save dessert planning for later and browse these easy homemade beignets when you want a warm, powdered-sugar finish.
Storage, Food Safety, and Reheating
Use refrigerated leftover turkey within 3 to 4 days. Keep the turkey chilled until you are ready to assemble the casserole, and do not use leftovers that have been held at room temperature for an extended period.
Store baked tetrazzini covered in the refrigerator. Reheat individual portions in the microwave or warm the casserole in the oven until the center reaches 165°F.
If you are planning ahead, you can prepare the components close to serving time, but remember that very cold pasta and sauce may require additional heating. The casserole is best when the noodles remain tender and the cheese is freshly melted.
Leftover tetrazzini makes a satisfying lunch the next day. Add a spoonful of broth or milk before reheating if the sauce has thickened in the refrigerator.
What to Serve After Dinner
This casserole is rich enough to be the main event, so lighter sides work well. A green salad with a bright vinaigrette, steamed green beans, or roasted carrots can balance the creamy sauce without competing with it.
For a sweet breakfast or snack the next day, keep our easy peach bread in mind. If you are hosting a casual gathering with extra turkey and snack cravings, our easy cheeseburger dip offers another hearty option for the table.
Easy Leftover Turkey Tetrazzini Recipe
Ingredients
Method
- Heat the oven to 350°F and grease a 9-by-13-inch baking dish. Cook the broken spaghetti in salted water until just shy of al dente, then drain well.
- Melt the butter in a large skillet or saucepan. Cook the onion and mushrooms for 5 to 7 minutes, until softened and most of the mushroom liquid has evaporated. Add the garlic and cook for about 30 seconds.
- Sprinkle the flour over the vegetables and stir for 1 minute. Gradually whisk in the broth, then the milk or half-and-half, and simmer for 3 to 5 minutes until thickened.
- Remove the sauce from the heat and stir in the sour cream, salt, pepper, Parmesan, and 1/2 cup of the mozzarella.
- Fold in the turkey, thawed peas, and cooked spaghetti. Transfer the mixture to the prepared baking dish and spread it evenly.
- Top with the remaining 1/2 cup mozzarella and optional breadcrumbs. Bake uncovered for 25 to 30 minutes, until bubbling and lightly browned. Rest for 5 to 10 minutes before serving.
Notes
Final Thoughts
This easy leftover turkey tetrazzini recipe is a practical way to turn holiday leftovers into a complete, crowd-pleasing meal. The combination of tender spaghetti, creamy mushroom sauce, turkey, peas, and melted cheese feels comforting from the first bite while requiring only basic cooking skills.
Remember the most important details: undercook the pasta slightly, cook the mushroom liquid away, add the sour cream and cheese off the heat, and let the casserole rest before serving. Those small steps make the texture creamy, cohesive, and pleasantly firm instead of watery or soft.
With a 9-by-13-inch dish and about an hour from start to finish, this is a dependable dinner for family, guests, or anyone looking for a delicious second act for leftover turkey. Add a green side, spoon the bubbling tetrazzini onto warm plates, and enjoy a cozy meal that tastes carefully planned rather than improvised.