Description

Leftover Turkey Pot Pie Gratin is a comforting and flavorful dish that transforms leftover turkey breast into a creamy, herb-infused casserole topped with tender sliced potatoes and melted Gruyere cheese. This recipe combines sautéed leeks, garlic, peas, and carrots in a rich gravy made with milk, chicken broth, and fresh herbs, then baked until golden and bubbly—perfect for a cozy family dinner or holiday leftovers makeover.

Ingredients

Scale

Dairy & Liquids

1 cup 1% milk (use half & half to make this more decadent if you wish)
1 tablespoon unsalted butter
2 cups low-sodium chicken bone broth (divided)
4 ounces shredded Gruyere cheese

Herbs & Seasonings

1 ¾ teaspoons kosher salt (or 1 chicken large Bouillon cube)
3 sprigs fresh thyme (plus ½ teaspoon fresh thyme leaves)
2 sprigs fresh sage
3 cloves garlic (minced)
¼ teaspoon fresh black pepper
3 tablespoons fresh parsley (chopped)

Produce

1 ½ cups leeks (from 3 large, halved and sliced, white part only, cleaned well)
2 cups frozen peas and carrots
1 pound Gold or Red potatoes (4 to 5 medium, peeled and sliced ⅛-inch thick with mandolin; peeled weight 12 ounces)

Protein & Thickening

1 ½ pounds leftover turkey breast (4 ¾ cups)
¼ cup cornstarch

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Instructions

Preheat the Oven: Preheat your oven to 375°F to get it ready for baking the gratin.
Infuse the Milk: In a large oven-safe enamel deep skillet with a fitted lid, gently bring the milk, ¼ teaspoon salt or bouillon cube, thyme sprigs, and sage to a simmer over low heat for about 5 minutes until aromatic. Then pour the infused milk into a bowl and set aside. Wipe the skillet clean for the next steps.
Sauté Vegetables and Turkey: Melt the butter in the same skillet. Add the sliced leeks and sauté for 4 to 5 minutes until soft. Stir in the minced garlic and cook until fragrant, about 1 minute. Next, add the leftover turkey breast, 1 ¼ teaspoons kosher salt, black pepper, 1 cup of chicken broth, frozen peas and carrots, 2 tablespoons chopped parsley, and the fresh thyme leaves. Cook the mixture for 3 to 4 minutes, allowing flavors to meld.
Thicken the Sauce: In a separate bowl, mix the remaining 1 cup chicken broth with ¼ cup cornstarch until smooth. Pour this mixture into the skillet with the turkey and vegetables, stirring constantly over medium heat. Cook for 3 to 4 minutes or until the sauce has thickened to a luscious gravy consistency.
Assemble the Gratin: Smooth the turkey mixture evenly in the skillet. Remove the fresh sage and thyme sprigs from the infused milk and pour the milk evenly over the turkey mixture. Arrange the peeled and thinly sliced potatoes on top in an overlapping spiral pattern starting from the outer edge until the meat mixture is completely covered. Sprinkle the shredded Gruyere cheese evenly over the potatoes. Cover the skillet tightly with foil or a lid to retain moisture during baking.
Bake and Broil: Place the covered skillet on the second rack from the top of the preheated oven and bake for about 1 hour, or until the potatoes are tender when pierced with a knife. Remove the lid or foil, then broil the gratin for approximately 3 minutes or until the Gruyere cheese is melted and golden brown. Keep a close eye to prevent burning.
Garnish and Serve: Sprinkle the remaining chopped parsley over the finished gratin for a fresh pop of color and flavor before serving immediately.

Notes

You can substitute half & half for the 1% milk for a richer, creamier sauce.
Ensure the skillet is oven-safe and has a fitted lid or use foil to cover the dish during baking.
Use a mandoline slicer to achieve consistently thin potato slices for even cooking.
Leftover turkey breast can be substituted with cooked chicken if desired.
The broiling step is key for achieving a beautifully browned cheese topping—watch carefully.
This dish can be made ahead up to the assembly stage and refrigerated before baking.

Prep Time: 30 minutes
Cook Time: 1 hour 15 minutes
Category: Main Dish
Method: Baking
Cuisine: American