Chicken Potpie

Preparation

1. Step 1

   Heat the oven to 400 degrees and line a sheet pan with foil.

2. Step 2

   Heat the olive oil in a medium (10-inch) skillet or Dutch oven (preferably oven-safe), over medium. Add the onion, carrots, celery and garlic and cook until just beginning to soften, about 3 minutes. Add the mushrooms, rosemary sprig and 1 teaspoon salt and cook, stirring occasionally, until mostly soft and much of the liquid has sweated out, about 10 minutes.

3. Step 3

   Stir in the butter until melted. Add the flour and cook, stirring, to coat the vegetables and to brown slightly, about 3 minutes. Add the broth by the cupful, stirring constantly with a wooden spoon and scraping up any bits from the bottom of the skillet. Bring to a simmer and stir until it thickens to make a gravy. Reduce the heat, stir in the cream and cook over low heat just until combined. Add the chicken, remaining 1 teaspoon salt and ½ teaspoon pepper, and stir over low heat until chicken is mostly cooked through, 3 to 5 minutes. Remove from the heat and discard the rosemary sprig. Stir in the peas; season the gravy to taste with salt and pepper.

4. Step 4

   If the pan you are using is not oven-safe, transfer the mixture to a deep, 10-inch pie pan or baking pan. Transfer the pan to the prepared sheet pan to collect any drips. Unroll the puff pastry and place it over the filling, making sure there is a 1-inch overhang on all sides, stretching slightly if needed. Trim any excess pastry with a sharp knife and set aside (see Tip).

5. Step 5

   Brush the top of the pie with the beaten egg, and carefully create several small slits in any pattern of your choosing to allow steam to escape while cooking. Scatter small rosemary sprigs over the top, along with fennel seed or pepper, if desired.

6. Step 6

   Bake until the puff pastry is puffed and golden brown, about 20 minutes. Reduce the oven temperature to 375 degrees and bake until the pastry is cooked through and the filling is bubbly, 15 minutes more. Remove from the heat and set aside for 10 to 15 minutes to cool slightly before serving.