This Leftover Turkey Casserole is exactly what I crave once the whirlwind of Thanksgiving cooking is behind me. It's creamy, hearty, and packed with all of my holiday favorites. It’s the perfect way to use up your leftover Thanksgiving turkey, mashed potatoes, and any leftover veggies while still making something that feels different.
I’ve shared a lot of my favorite holiday recipes lately, and honestly, the Thanksgiving leftovers might be the best part—especially this Leftover Turkey Casserole. I’m such a sucker for all the holiday sides and can't wait to snack on them for days, whether it’s my green bean casserole, some stuffing, or a little leftover cranberry sauce on the side. This cozy, comforting casserole feels indulgent without much work, which is exactly what I need after a big Thanksgiving dinner.
I made my Thanksgiving leftovers into a casserole for the first time back in 2020, and I've been doing it ever since! Honestly, I might like it better than Thanksgiving dinner.
What's In This Blog Post?
Ingredients Needed
Before we get started, here’s everything you’ll need to make this cozy Leftover Turkey Casserole. Most of the ingredients are probably already sitting in your fridge after Thanksgiving, which makes this an easy recipe to pull together the next day.
For the Casserole
- Leftover Turkey - Use white or dark meat. If you’re out of turkey, leftover chicken or rotisserie chicken is perfect.
- Leftover Mashed Potatoes - Used as the casserole topping. You can also use prepared mashed potatoes, instant potatoes, or even leftover stuffing for a fun variation.
- Frozen Peas - Adds color and sweetness. Frozen mixed vegetables or canned corn also work well.
- Celery - Adds crunch and flavor. You can use fennel, green bell pepper, or skip it if you don’t have any.
- Carrots - Adds sweetness and texture. Frozen sliced carrots or even parsnips can be substituted.
- Onion - Adds savory flavor. Swap in shallots, leeks, or onion flakes in a pinch.
- Butter - Adds richness and helps form the roux for the homemade cream of chicken soup. You can substitute margarine or a neutral oil in a pinch, though the flavor will be slightly different.
For the Homemade Cream of Chicken Soup
- Flour - Used to thicken the sauce. All-purpose flour works best, but you can sub a 1:1 gluten-free flour blend if needed.
- Chicken Broth - Gives the sauce its savory base. Vegetable broth or turkey broth both work as great substitutes.
- Chicken Bouillon or Better Than Bouillon - Enhances the depth of flavor. If you don’t have any, simply add a pinch more salt or use a richer broth.
- Milk - Adds creaminess. Any milk works—2%, skim, or even unsweetened oat, almond, or soy milk.
- Soy Sauce - Enhances the savory, “umami” flavor and deepens the color. You can swap in Worcestershire sauce, tamari, or coconut aminos.
- Seasoning - This blend of celery salt, onion powder, and garlic powder adds savory depth and classic comfort-food flavor to the casserole. If you’re missing one, you can easily substitute: use regular salt with a pinch of celery seed for celery salt, minced fresh onion for onion powder, or a small clove of fresh garlic in place of garlic powder.
Tips and Tricks for Success
- Use warm mashed potatoes for easier spreading across the casserole dish.
- Dice the turkey into thick slices or cubes for even heating.
- Sauté vegetables until al dente for the best texture.
- Stir in leftover gravy for an even creamier sauce.
- Try fun twists: add green beans, corn, or even cooked egg noodles for variation.
- Freeze leftovers in an airtight container for an easy comfort food dish later.
- Assemble ahead of time and cover with plastic wrap if you need a break from cooking.
How to Make Leftover Turkey Casserole
With everything prepped, here’s exactly how to assemble and bake your Leftover Turkey Casserole. It comes together easily and makes the perfect low-effort meal after a big holiday.
- Preheat the oven to 350ºF.
- Dice the carrots, celery and carrots.
- Add the butter to a saucepan and melt it over medium heat.
- Add in the diced vegetables and sauté until the carrots are al dente.
- Add in the cream of chicken soup and leftover turkey and mix together.
- Allow it to begin to simmer.
- Remove it from the heat.
- Stir in the peas.
- Place the mixture into a casserole dish.
- Top with leftover mashed potatoes.
- Bake in the oven for about 20 minutes or until the mixture is bubbling.
- Optional: broil for 2-3 minutes to make the potatoes crispy.
- Top with parsley and serve hot.
Frequently Asked Questions
Yes! You can assemble the entire casserole up to 24 hours in advance. Cover it tightly and store it in the refrigerator, then bake as directed—adding 5–10 extra minutes if it’s going into the oven cold.
Cooked turkey is safe in the fridge for 3–4 days, which makes it perfect for a casserole the day after Thanksgiving. If you need more time, freeze the turkey (or the assembled casserole) for up to 2–3 months.
Absolutely. Let the casserole cool completely, then wrap it well or transfer portions to airtight containers. Freeze for up to 3 months and reheat in the oven at 350°F until warmed through.
Stuffing, green beans, corn, leftover veggies, and even gravy can be mixed in for extra flavor. Just avoid anything with a very high water content so the casserole doesn’t become runny.
Yes. Leftover rotisserie chicken or roasted chicken works perfectly. The flavors stay similar, and the cooking time doesn’t change.
This usually happens if the veggies weren’t sautéed long enough or if the sauce wasn’t thickened before assembling. Let the cream of chicken mixture simmer a few minutes to tighten up before baking.
Nope! You can swap them for leftover stuffing, pre-made mashed potatoes, or even a quick batch of instant potatoes. You can also top it with puff pastry or biscuits for a different twist.
Use whole milk, add a splash of heavy cream, or stir a bit of leftover gravy into the sauce. You can also sprinkle in some shredded cheddar or mozzarella.
A 9×13 casserole dish or similar shallow dish works best. A wider pan helps the filling heat evenly and gives the mashed potatoes room to get a little crispy.
Yes! Cheese isn’t traditional in a Thanksgiving-style casserole, but it’s delicious. Stir cheese into the filling or sprinkle it over the mashed potatoes before baking.
Recipe
Ingredients
- 2 stalks celery diced
- 2 large carrots diced
- ½ yellow onion diced
- 1 cup frozen peas
- 2 cups leftover turkey diced
- 2 cups leftover mashed potatoes
- 2 cans cream of chicken soup
Instructions
- Preheat the oven to 350ºF.
- Dice the carrots, celery and carrots.
- Add the butter to a saucepan and melt it over medium heat.
- Add in the diced vegetables and sauté until the carrots are al dente.
- Add in the cream of chicken soup and leftover turkey and mix together.
- Allow it to begin to simmer.
- Remove it from the heat.
- Stir in the peas.
- Place the mixture into a casserole dish.
- Top with leftover mashed potatoes.
- Bake in the oven for about 20 minutes or until the mixture is bubbling.
- Optional: broil for 2-3 minutes to make the potatoes crispy.
- Top with parsley and serve hot.
Notes
- Make-Ahead Instructions: You can assemble the entire casserole up to 24 hours in advance. Cover it tightly and store it in the refrigerator, then bake as directed—adding 5–10 extra minutes if it’s going into the oven cold.
- Freezer Instructions: Let the casserole cool completely, then wrap it well or transfer portions to airtight containers. Freeze for up to 3 months and reheat in the oven at 350°F until warmed through.
- Cream of chicken soup made from scratch tastes amazing but of course you can use two cans of the premade kind if you want.
