3 pounds
russet potatoes, peeled and cut into 2-inch cubes
2
bay leaves
½ cup (1 stick)
salted butter, softened
¾ cup
whole milk, warmed
1 teaspoon
garlic powder
Sea salt, to taste
Freshly cracked black pepper, to taste
Turkey Filling
½ cup (1 stick)
salted butter, cut into pieces
1 cup
chopped yellow onion, (from 1 medium onion)
2
celery ribs, cut into ¼-inch pieces
2 medium
carrots, peeled and cut into ¼-inch pieces
½ cup
all-purpose flour
1 teaspoon
kosher salt
½ teaspoon
freshly cracked black pepper
1 teaspoon
garlic powder
1 teaspoon
minced fresh thyme leaves, (optional)
¾ cup
whole milk, (warmed)
1 ½ cups
chicken stock, (warmed)
1 cup
frozen green beans
3 cups
chopped cooked turkey or chicken
Parsley, minced, (optional)
Method
Make the garlic mashed potatoes. Fill a large pot with water. Add the salt, the potatoes, and bay leaves. Bring to a boil over high heat. Reduce heat to medium and boil until fork-tender but not falling apart, about 15-20 minutes.
Meanwhile, make the turkey filling. In a large, deep ovenproof skillet or braiser (see Note 1), melt the butter over medium heat. Add in the onion, celery, and carrots and cook, stirring occasionally, until the onions are tender and translucent, about 5 minutes. Stir in the flour, salt, pepper, garlic powder, and thyme to create a thick paste.
Slowly stir in the milk. Once the milk is fully incorporated, slowly stir in the chicken stock. Simmer, whisking continuously, until mixture has thickened, about 5 minutes. Stir in the green beans and turkey.
Preheat the oven to 400°F with a rack in the center position.
Drain the potatoes. Return the potatoes to the pot and return the pot to low heat. Remove the bay leaves.
Use a ricer or potato masher to mash the potatoes. Add ½ cup softened butter and ¾ cup warmed milk, stirring quickly until incorporated. Season with 1 teaspoon garlic powder and salt and pepper to taste.
Spread the mashed potatoes over the turkey filling creating soft peaks as you spread it (see Note 2). Bake until lightly browned and the filling is bubbling, about 30 minutes.
Notes
If you don’t have an ovenproof skillet or braiser, you can use a regular skillet for the stovetop cooking and transfer the filling to a 9 x 13-inch baking dish to finish in the oven.
If your mashed potatoes reach the top of your baking dish, place the casserole on top of a rimmed sheet pan to catch any overflow.