This leftover turkey casserole is an American classic called a Tetrazzini and a favorite dish to make with leftover Thanksgiving turkey. Good thing it works with chicken too, because this comfort food casserole is something you'll want to make more often than just after Thanksgiving.
Classic recipes are filled with butter, heavy cream and white pasta. While these versions might taste good, I wanted a healthier dish to fit with today's healthier eating preferences.
I switched out the white pasta for whole wheat, made the sauce with whole wheat pastry flour instead of white flour, used homemade turkey broth instead of cream and added peas for color and a little extra vegetables. Parmesan-Reggiano cheese, dry sherry and a little nutmeg add flavor.
Make a Roux: Classic Sauce Thickener
The base for the sauce is called a roux (pronounced roo), a classic combination of cooked flour and fat used as a thickener in sauces.
Traditionally white flour is used. I've used whole wheat pastry flour instead, giving it a nutty flavor and golden color. For the fat, I've combined a little butter with olive oil instead of all butter. You can use a GF flour blend as well.
Three Steps to Make the Casserole
There are three steps to putting this casserole together:
- Make the sauce
- Cook the pasta and vegetables
- Mix with turkey and bake
Just add a tossed green salad for balance and dinner is ready.
📖 Recipe
Leftover Turkey Casserole (Tetrazzini)
Equipment
- casserole baking dish
Ingredients
Crumb Topping
- ¼ cup toasted breadcrumbs preferably homemade, whole wheat or GF
- 2 tablespoons grated Parmesan-Reggiano cheese
- 1 teaspoon extra virgin olive oil
Sauce
- 1 tablespoon unsalted butter
- 2 tablespoons extra virgin olive oil
- ¼ cup all purpose flour or GF blend flour
- 2 cups turkey or chicken broth low or no sodium
- ⅓ cup grated Parmesan-Reggiano cheese
- 2 tablespoons dry sherry optional
- 2 teaspoons fresh chopped thyme leaves
- ⅛ teaspoon freshly grated nutmeg
- 2 teaspoons fresh lemon juice
- salt and pepper to taste
Filling
- 8 ounces penne pasta whole wheat or gluten-free
- 1 tablespoon extra virgin olive oil
- ½ medium onion chopped fine
- 8 ounces fresh mushrooms cleaned, stemmed, and sliced thick
- 2 cloves garlic chopped fine
- 12 ounces diced cooked turkey or chicken about 3 cups chopped
- ½ cup peas thawed if frozen
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Instructions
Make Topping
- Mix toasted breadcrumbs, cheese and olive oil in a small bowl and set aside. Heat oven to 375 degrees.
Make the Sauce
- Place the butter and olive oil in a medium saucepan over medium heat. When butter and oil are bubbly, add the whole wheat flour and whisk together, cooking one minute to remove the raw flour taste. Slowly add the broth, whisking to incorporate and cook until it starts to thicken. When it's ready it will coat the back of a spoon and you'll be able to draw your finger through it.
- Off the heat, stir in the cheese, dry sherry, thyme, nutmeg and lemon juice. Season with a little salt and pepper. Set sauce aside.
Cook the Pasta
- Bring water to a boil in a 4-5 quart pan. Add a tablespoon of kosher or sea salt to the water; add pasta and cook according to package directions. Drain and set aside.
Cook Vegetables
- While pasta is boiling, cook the onions in olive oil over medium to medium-low heat in a saute pan or skillet. When the onions are soft and translucent, add the mushrooms. Stir and cook the mushrooms until they are are browned and most of their moisture is gone. Stir in the garlic and cook another 30 seconds. Stir in the turkey (or chicken) and peas.
Assemble the Casserole
- In a large bowl, mix the cooked pasta together with the sauce, vegetables and turkey (or chicken). Spray a medium casserole, about 1 ½ - 2 quarts with non-stick spray and pour the pasta mixture in. Sprinkle with the breadcrumbs and bake until hot and crumbs are golden on top, 30-45 minutes. Use a digital thermometer and cook until casserole reaches 165°F.
