This one-pan pie is the perfect option for a comforting and hearty weeknight dinner. Using a creative substitute for cream, it is also completely dairy-free.
Preheat oven to 190°C/375°F. Season the chicken evenly with 1 tsp of the salt. Add 1 tbsp of the olive oil to a 10-inch cast iron skillet (see note 3) and set over medium-high heat. Once shimmering, add the chicken, working in batches so as not to overcrowd the pan, and cook until it is browned and golden - about 2-3 minutes per side. Remove from the pan and set aside.
Meanwhile, drain the cashews and add them to the jar of a blender along with 60ml (¼ cup) cold water. Blend on high for 1-2 minutes until very smooth. Transfer the cashew cream to a small bowl and set aside.
Reduce the heat to medium and add the remaining oil. Add the celery, carrot and leek along with the remaining ½ tsp of salt. Cook until softened, about 5 minutes, before stirring in the garlic and thyme. Cook for 1 minute longer.
Add the flour and stir it into the vegetables. Cook for 2 minutes longer, stirring constantly. Pour over the wine and cook until it is reduced and the alcoholic smell has dissipated, 1-2 more minutes.
Pour over the stock and stir to combine. Bring to a simmer. Stir in the cashew cream and frozen peas. Add the chicken, along with any accumulated juices. Remove from the heat.
On a lightly floured surface, roll the puff pastry to fit the top of the skillet. Place it over the filling. Brush with the beaten egg and season with salt and pepper, if desired. Place on a rimmed baking tray (to catch any drips) and bake until the pastry is deeply golden and the filling is bubbling, about 30 minutes. Allow to cool for 10 minutes before serving.
Notes
For best results, use unsalted stock so you can control the seasoning of the final dish.
For best results, measure salt by weight, as different salts vary in crystal size and density.
A 10-inch cast iron skillet is ideal as it goes from stovetop to oven in one vessel. If you don't have one, make the filling in any wide, heavy-based pan, then transfer it to a lightly greased 23cm (9-inch) round or 20x20cm (8-inch square) baking dish, at least 5cm (2 inches) deep, before topping with the pastry and baking.