Directions
<ol class="no-list-style"><li class="MethodStepper"><h4 class="step-title">Step 1</h4>Start with the pastry. In a large bowl or food processor, combine the flour and salt. Add the cold cubed butter (cold butter is essential as it creates steam pockets during baking, resulting in flaky layers). Rub the butter into the flour using your fingertips or pulse in the food processor until the mixture resembles breadcrumbs.</li><li class="MethodStepper"><h4 class="step-title">Step 2</h4>Add the beaten egg and gradually add the ice-cold water, 1 tablespoon at a time, mixing until the dough just comes together. Don't overwork the dough or add too much water as this will develop the gluten and make your pastry tough. The dough should hold together when pressed but not be sticky.</li><li class="MethodStepper"><h4 class="step-title">Step 3</h4>Divide the dough into two portions – about 2/3 for the base and 1/3 for the top. Flatten each into discs, wrap in cling film, and refrigerate for at least 30 minutes. Chilling relaxes the gluten and firms up the butter, ensuring a tender, flaky result.</li><li class="MethodStepper"><h4 class="step-title">Step 4</h4>While the pastry chills, prepare your filling. In a large saucepan, melt half the butter over medium heat. Add the chicken pieces and cook until lightly golden on all sides, about 5-6 minutes. They don't need to be fully cooked through. Remove the chicken and set aside.</li><li class="MethodStepper"><h4 class="step-title">Step 5</h4>In the same pan, add the remaining butter. Once melted, add the leek and carrots, cooking until softened but not browned, about 5-7 minutes. The moisture from the vegetables will help deglaze the pan, capturing all the flavorful bits from the chicken.</li><li class="MethodStepper"><h4 class="step-title">Step 6</h4>Sprinkle the flour over the vegetables and stir continuously for 2 minutes to cook out the raw flour taste. This roux will thicken your sauce to the perfect consistency – not too runny that it makes the pastry soggy, and not too thick that it becomes claggy.</li><li class="MethodStepper"><h4 class="step-title">Step 7</h4>Gradually add the chicken stock, stirring constantly to prevent lumps forming. Bring to a simmer and let it thicken for 2-3 minutes. Then add the cream, Dijon mustard, tarragon, salt, and pepper. The mustard adds a subtle tang that balances the richness of the cream.</li><li class="MethodStepper"><h4 class="step-title">Step 8</h4>Return the chicken to the pan along with the frozen peas. Simmer gently for 5 minutes, then remove from heat and allow to cool completely. A hot filling will melt your pastry before it bakes, preventing a crisp base.</li><li class="MethodStepper"><h4 class="step-title">Step 9</h4>Preheat your oven to 200°C (180°C fan/gas mark 6). Take the larger disc of pastry from the fridge and roll it out on a lightly floured surface to about 3-4mm thickness, making it large enough to line your pie dish with some overhang.</li><li class="MethodStepper"><h4 class="step-title">Step 10</h4>Carefully drape the pastry over your rolling pin to transfer it to the pie dish. Gently press it into the corners without stretching the dough (stretching causes shrinkage). Trim any excess, leaving a small overhang. Prick the base several times with a fork to prevent air bubbles forming.</li><li class="MethodStepper"><h4 class="step-title">Step 11</h4>Pour the cooled chicken filling into the pastry case, creating a slight mound in the center. Roll out the remaining pastry disc for the lid to about the same thickness as the base.</li><li class="MethodStepper"><h4 class="step-title">Step 12</h4>Brush the rim of the pie with beaten egg, then carefully place the pastry lid on top. Press the edges together to seal, then trim any excess. Crimp the edges using your fingers or a fork for a decorative finish that also ensures a good seal.</li><li class="MethodStepper"><h4 class="step-title">Step 13</h4>Make a small hole or a few slits in the center of the pie to allow steam to escape during baking. This is crucial as trapped steam can cause your pastry to become soggy. Brush the entire surface with beaten egg for a beautiful golden sheen.</li><li class="MethodStepper"><h4 class="step-title">Step 14</h4>If you have any pastry scraps, you can create decorative leaves or shapes to place on top of the pie. Brush these with egg wash too.</li><li class="MethodStepper"><h4 class="step-title">Step 15</h4>Bake in the preheated oven for 35-40 minutes until the pastry is deeply golden and crisp. If the top begins to brown too quickly, cover loosely with foil and continue baking.</li><li class="MethodStepper"><h4 class="step-title">Step 16</h4>Once baked, let the pie rest for 5-10 minutes before serving. This allows the filling to settle and makes it easier to slice. The tarragon's anise-like flavor will have infused beautifully throughout the creamy filling, complementing the tender chicken and vegetables.</li></ol>