There’s something particularly good about turning leftover roast turkey into a dinner that feels completely different the second time around. This Cheesy Leftover Turkey & Potato Casserole layers tender potatoes and pieces of cooked turkey in a rich homemade cheese sauce, then finishes everything under a bubbling golden layer of cheddar.

Instead of using canned soup, we’re making a simple creamy sauce with butter, flour, milk and cheese. It coats the potatoes and turkey as the casserole bakes, keeping the meat moist while creating that gooey, creamy texture you want from a comfort-food dinner.

It’s especially handy after Thanksgiving when there’s a container of turkey taking up half the fridge, but there’s nothing particularly seasonal about it. Leftover roast turkey, turkey breast or even cooked chicken can all work here.

A Second Dinner That Doesn’t Taste Like Leftovers

The problem with leftover turkey isn’t usually finding something to do with it. It’s finding something that doesn’t feel like you’re eating Thanksgiving dinner again.

This casserole takes it in a completely different direction.

Instead of gravy, stuffing and cranberry sauce, the turkey gets folded between tender potatoes and a creamy cheddar sauce. Mozzarella scattered over the top gives the finished casserole extra stretch, while cheddar provides most of the flavor.

Serve it straight from the baking dish while the sauce is still bubbling around the edges.

Why Parboil the Potatoes First?

It can be tempting to put raw potatoes straight into the casserole, but giving them a short head start makes this recipe much more reliable.

Slice the potatoes fairly thinly and simmer them for around 6–8 minutes. You’re not trying to cook them completely. They should be beginning to soften but still firm enough to handle without falling apart.

Once they’re layered into the casserole, they’ll finish cooking in the cheese sauce.

This also means you don’t have to bake the casserole for an hour waiting for stubborn potatoes to soften while your already-cooked turkey becomes dry.

The Creamy Cheese Sauce

This is where the casserole gets good.

Start with melted butter and flour to create a simple roux. Gradually whisk in the milk until you have a smooth white sauce, then add mature cheddar.

A little Dijon mustard adds depth without making the sauce taste strongly of mustard, while thyme works particularly well with cooked turkey.

Keep some of the cheese back for the top. I like using mostly cheddar with a little mozzarella, because you get both the stronger cheddar flavor and that stretchy melted-cheese finish.

Got Leftover Gravy Too?

Here’s an easy Thanksgiving variation.

Replace around ½ cup of the milk with leftover turkey gravy.

It makes the sauce richer and gives you another way to clear Thanksgiving leftovers from the refrigerator. Depending on how salty your gravy is, reduce the additional salt until you’ve tasted the finished sauce.

Ingredients You’ll Need

Cooked Turkey

Use cooked turkey cut or torn into bite-size pieces. A mixture of white and dark meat is particularly good because the darker meat stays very juicy.

You can also make the casserole with leftover roast chicken.

Potatoes

Yukon Gold or another all-purpose/waxy potato works nicely because the slices become tender while still holding their shape.

Cheddar and Mozzarella

Mature or sharp cheddar forms the base of the sauce.

Mozzarella is optional, but it’s worth adding if you want that gooey cheese pull when the first serving comes out of the dish.

Milk

Whole milk gives the sauce a richer texture, although 2% milk will also work.

Dijon Mustard and Thyme

These stop a fairly simple cheese sauce from tasting flat. Neither needs to dominate the dish; they’re there in the background.

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How to Make Cheesy Leftover Turkey & Potato Casserole

1. Prepare the potatoes

Preheat the oven to 190°C / 375°F.

Slice the potatoes into approximately ¼-inch slices.

Add them to a saucepan of salted boiling water and cook for 6–8 minutes, until they’re beginning to soften but aren’t fully cooked.

Drain well.

2. Make the sauce

Melt the butter in a saucepan over medium heat.

Add the flour and cook for approximately one minute while stirring.

Slowly add the milk, whisking continuously so the sauce remains smooth.

Cook for a few minutes until it begins to thicken.

3. Make it cheesy

Reduce the heat and stir in the Dijon mustard, thyme, black pepper and 1½ cups of cheddar.

Continue stirring until the cheese has melted and the sauce is smooth.

Taste before adding additional salt, particularly if your turkey was well seasoned.

4. Build the casserole

Lightly grease a casserole dish.

Arrange approximately half of the potatoes across the bottom. Scatter half of the cooked turkey over them and spoon over some of the cheese sauce.

Repeat with the remaining potatoes and turkey.

Pour the remaining sauce evenly over the top.

5. Add the gooey top

Sprinkle over the remaining cheddar and mozzarella.

Don’t worry if a few potato slices remain visible around the edges — they’ll become beautifully golden while the cheese bubbles in the centre.

6. Bake

Bake uncovered for 25–30 minutes, or until the casserole is bubbling and the potatoes are completely tender.

For extra colour, place it under the broiler/grill briefly at the end.

Allow it to rest for 5–10 minutes before serving. The sauce will thicken slightly as it stands.

What to Serve With It

This is already a fairly substantial dinner, so I’d keep the sides simple.

Steamed green beans, broccoli or a crisp green salad are enough to balance the rich cheese sauce.

And if creamy potato dinners are exactly what you’re looking for, try our Creamy Cheesy Ham and Potato Soup when you’ve got leftover ham rather than turkey.

You can also browse our Leftover Recipes for more ways to turn cooked meat and other odds and ends into another meal.

How Long Is Leftover Turkey Good For?

If you’re making this after Thanksgiving, don’t forget that the clock has already started on your cooked turkey.

The USDA recommends refrigerating cooked turkey promptly and using refrigerated cooked turkey within 3–4 days. Leftovers should also be reheated to 165°F / 74°C. Food Safety and Inspection Service

For the external link in the article, I’d naturally link “USDA guidance for handling cooked turkey and leftovers” to:

USDA Turkey Basics: Handling Cooked Dinners

Can You Make It Ahead?

Yes. Assemble the casserole, cover it and refrigerate it until you’re ready to bake.

Because you’ll be starting with a cold casserole, allow a little additional oven time and make sure the centre is thoroughly heated before serving.

For food safety, I wouldn’t use this method as a way of extending turkey that’s already approaching the end of its refrigerated storage window.

Can You Use Thanksgiving Leftovers?

Definitely — and that’s one of the best times to make it.

Cooked Thanksgiving turkey is the obvious starting point, but the optional gravy variation means you can use another leftover at the same time.

You could even serve a spoonful of cranberry sauce alongside the casserole rather than mixing it through the cheese sauce. The sweet-tart cranberry works surprisingly well against creamy potatoes and cheddar.

That gives you a Thanksgiving leftovers dinner without simply reheating the original plate.