Puff Pastry Chicken and Leek Casserole

Prep time: 30 min
Cook time: 60 min
Servings: 8
Yield: 8 servings

Description

Leeks take center stage in this casserole recipe, creating a rich base for tender chicken and veggies. Puff pastry brings an irresistible golden crunch.

Ingredients

1 pound boneless, skinless chicken thighs
2 medium carrots, chopped
2 stalks celery, chopped
1 large leek, sliced
1 cup peas
2 tablespoons chopped fresh parsley
2 large bay leaves
1 tablespoon minced garlic
2 teaspoons minced shallot
2 teaspoons dried tarragon
1 1/2 teaspoons kosher salt
1 teaspoon dried basil
1 teaspoon ground black pepper
2 1/2 cups milk
4 tablespoons salted butter
3 tablespoons all-purpose flour
2/3 cup heavy whipping cream
1 1/2 teaspoons Dijon mustard
1 (17 1/2 ounce) package frozen puff pastry, thawed
1 large egg, beaten

Directions

1 Preheat the oven to 350 degrees F (175 degrees C). Grease a 9x13-inch baking dish.
2 Place chicken, carrots, celery, leek, peas, parsley, bay leaves, garlic, shallot, tarragon, salt, basil, and black pepper in a large saucepan. Stir in milk until blended; bring to a simmer. Cover saucepan; simmer for 15 minutes. Remove from heat; cool slightly.
3 Strain milk into a bowl; set aside. Separate chicken and vegetables into separate bowls. Tear chicken into bite-sized chunks when cool enough to handle.
4 Melt butter in the same saucepan over medium heat. Stir in flour until smooth; continue cooking and stirring until mixture thickens, turns golden, and becomes a roux. Gradually add strained milk, stirring until it becomes a sauce. Stir in heavy cream and Dijon mustard, then add chicken and vegetables. Remove from heat; cool slightly, about 5 minutes.
5 Pour chicken mixture into the prepared baking dish. Roll out puff pastry; place over casserole, overlapping to completely enclose filling. Brush pastry top with beaten egg; make several vents in pastry top using a sharp knife.
6 Bake in the preheated oven until golden, 30 to 40 minutes.