Leftover Turkey Casserole: Creamy Leek Potato Hotpot (Better Than Pie)

Turning Leftovers into Luxury: The Ultimate Leftover Turkey Casserole

That smell. Oh my gosh, that smell of bubbling cream sauce and crispy baked potatoes right after the holidays is pure auditory comfort food. You can practically hear the oven sighing happily as the top layer turns gloriously golden brown.

This dish is about taking the best elements of a roast dinner and combining them into one perfect, deeply savory hug.

This recipe is the ultimate post holiday champion, making tired, leftover turkey (which, let's be honest, can be a little dry) feel luxurious again. It gives that rather bland bird a spectacular second life.

It’s fast, incredibly cheap, and minimizes food waste, which makes my wallet sing after a costly holiday season.

Forget another dry turkey sandwich for lunch. We're building a proper, cozy, creamy hotpot today, and this version is absolutely the one you need. If you're looking for the cheesiest version, you might also love my guide to Turkey Casserole: Ultimate Creamy Leftover Bake with Cheesy Crumb . Let's crack on with the good stuff.

Why We Call This a 'Proper Hotpot' (Casserole Origin)

Across the pond, a hotpot usually implies a dish topped with sliced potatoes, unlike the breadcrumb or pastry topping often found on US casseroles. This is a crucial distinction. We are using that starchy goodness to create a perfect, crisp lid.

The combination of the creamy, slow simmered leek and turkey base topped with thinly layered potatoes results in something rich but never heavy. It balances the sweetness of the leeks with the earthiness of the turkey, providing layers of flavor you just don't get from a soup based casserole. It's brilliant.

Ditching the Dry Bird: The Secret to Creamy, Moist Turkey

We are absolutely banning the canned cream of anything soup here, okay? The secret to truly spectacular leftover turkey casserole is creating your own velvety béchamel style base. We start by building a simple roux (equal parts fat and flour) using the fragrant butter from cooking the leeks.

Chef's Note: Using rich turkey stock and full fat milk ensures a deeply flavored, lump free sauce that perfectly rehydrates and hugs every piece of cubed turkey. This prevents the turkey from drying out further in the oven.

Prep Time vs. Cook Time: A Quick Overview

Because the turkey is already cooked, the prep time is delightfully minimal. We spend most of our active time making the sauce and slicing those potatoes precisely. This dish requires about 20 minutes of active work before it happily sits in the oven for a final golden bake.

Shopping List and Essential Substitutions for Your Turkey Hotpot

This recipe is designed to be highly flexible it’s a leftover dish, after all! Don't stress if you're missing one specific item. Here’s what you need and what you can swap out.

The Key Components: Leftover Roast Turkey and Fresh Leeks

The texture contrast between the tender meat and the sweet, soft leeks is foundational to this recipe. Make sure your turkey is cubed or shredded into bite sized pieces.

Dairy Decisions: Milk, Cream, and Cheese Options

The dairy is what transforms the flour and fat into that luxurious sauce. Don't skimp on fat content here; flavor lives in the fat!

Whole milk is strongly recommended for the sauce viscosity. If you use skim milk, the sauce will be thinner and less rich. You might need an extra tablespoon of flour to compensate. I also throw in a bit of sharp cheddar over the potatoes for extra crunch, but that’s optional.

Essential Pantry Items: Ratios for a Robust Roux

A roux is simply melted butter and flour cooked together. The ratio is usually 1:1, by weight or volume. You must cook the roux for at least two minutes to eliminate the raw flour taste; otherwise, your casserole will taste slightly metallic.

The stock is equally vital. If you only have chicken stock on hand, that’s perfectly fine! Just make sure it’s low-sodium so you can control the final salt level.

Making it gluten-free or dairy-free (Quick Adjustments)

• gluten-free Fix: Swap the all-purpose flour for a measure for-measure gluten-free blend or cornstarch. If using cornstarch, mix it with cold water first (a slurry) before stirring it into the warm stock/milk mixture off the heat.
• dairy-free Fix: Use a high-quality, unsweetened oat milk or cashew milk (for richness). Substitute the butter with a good plant based butter alternative. The final sauce will be slightly thinner, but still fantastic.

How to Make the Best Leftover Turkey Casserole: step-by-step

Preheat your oven to 375°F (190°C) and lightly grease your favorite 9x13 inch casserole dish. This is going to be messy and amazing.

Phase 1: Preparing the Aromatics and Cooking the Roux

1. Sauté the Leeks: Melt 4 tablespoons of butter in a large, deep skillet over medium heat. Add the thinly sliced leeks (white and light green parts only) along with a generous pinch of salt. Cook them slowly for 5- 7 minutes until they are totally softened and sweet; don't let them brown!
2. Make the Roux Base: Sprinkle 4 tablespoons of all-purpose flour over the softened leeks. Stir constantly and cook for 1 full minute. You want to smell a slightly nutty aroma, which means the raw starch flavor is gone. This step is critical.

Phase 2: Building the Velvety Cream Sauce

3. Add Liquid Slowly: Remove the pan from the heat briefly. This prevents the liquid from boiling immediately and helps avoid lumps. Slowly, very slowly , whisk in 2 cups of warm turkey stock, ensuring the mixture is smooth before adding the next splash. Now, whisk in the remaining 1 cup of whole milk.
4. Thicken the Sauce: Return the pan to medium heat. Bring the mixture to a gentle simmer, stirring constantly with a rubber spatula or whisk. The sauce will thicken dramatically as soon as it simmers. It should be thick enough to easily coat the back of a spoon.
5. Finish the Filling: Take the pan off the heat immediately. Stir in the 4 cups of cubed turkey, 1 cup of frozen peas, 1 teaspoon of Dijon mustard, and any remaining fresh herbs (like thyme). Taste the sauce and adjust the salt and pepper.

Phase 3: Combining, Topping, and Baking to Golden Perfection

6. Assemble and Layer: Pour the entire turkey and leek mixture into your prepared casserole dish, spreading it out evenly.
7. The Potato Topping: Using a mandoline or a very sharp knife, slice your peeled potatoes as thinly and uniformly as possible (aim for 2 3mm). Arrange them over the filling in neat, overlapping rows. This makes it look really professional!
8. Oil and Season: Brush the potatoes generously with olive oil or melted butter. Season heavily with flaky sea salt and cracked black pepper. Sprinkle with grated cheddar cheese if using.
9. Bake: Bake for 30– 35 minutes.

Visual Guide: Knowing When the Casserole is Ready

How do you know it’s done? First, the creamy sauce should be visibly bubbling up around the edges of the potato top. Second, the potatoes themselves must be fork tender when poked and beautifully golden brown and crisp on the surface.

If they are browning too fast but aren't tender yet, cover the dish loosely with foil for the last 10 minutes.

Troubleshooting and Storage: Expert Tips for Your Leftover Turkey Casserole

I once baked a casserole and forgot to cook the roux long enough it tasted like wet flour, and I had to throw the whole thing out. Learn from my mistake! Here are the common pitfalls.

Preventing a Watery Sauce: Moisture Management Strategies

If your sauce comes out thin, it’s usually because you didn’t cook the roux long enough or you didn't allow the sauce to simmer and reduce. Fix: If the sauce looks too thin before adding the turkey, mix 1 tablespoon of cornstarch with 2 tablespoons of cold water to create a slurry.

Stir the slurry into the simmering sauce and let it bubble for 1 minute to thicken instantly.

Achieving a Crunchy, Golden Top Layer (No Soggy Breadcrumbs)

Using potatoes instead of breadcrumbs already helps immensely, but they still need help. The key is dryness and fat. Pat those sliced potatoes completely dry with a paper towel before layering them. Then, ensure they are fully brushed with oil or melted butter.

This fat promotes browning and crispness. Do not cover the casserole while it bakes.

make-ahead Instructions for Busy Cooks

This is a fantastic dish to prep ahead!

• make-ahead Prep: Prepare the entire creamy filling (Steps 1 5). Pour it into the casserole dish, but do not add the potatoes yet . Cover and refrigerate for up to 24 hours.
• Baking Cold: When ready to bake, slice and top with potatoes, oil, and seasoning. Add 10– 15 minutes to the total bake time since the filling is coming from a cold state.
• Storage: Leftovers keep well in an airtight container in the fridge for 3 4 days.
• Freezing: Casseroles freeze beautifully! Bake the casserole completely, let it cool, then cover tightly with foil and freeze for up to 3 months. To reheat, thaw overnight in the fridge and bake covered at 350°F (175°C) until hot throughout (about 40 minutes).

What to Serve with Your Creamy Turkey Hotpot (Pairings)

Because the hotpot is rich and creamy, you want something light and acidic to balance it out.

• A sharp, simple side of steamed green beans dressed with a squeeze of lemon juice is perfect.
• If you still have leftovers from the big meal, serving this alongside a tart and nutty dish like my Healthier Sweet Potato Casserole with Crispy Pecan Crumble makes a great full plate.
• If you loved the cozy, creamy idea but need a quick alternative for other leftovers, check out my guide on a simple Chicken Stuffing Bake: Cozy Comfort Casserole, Ready in 1 Hour .