Step 1

Preheat oven to 375°F/190°C. Lightly grease the inside of 6 x 12oz/1½ cup ramekins or an 8 cup baking dish or casserole. Set aside.

Step 2

Preheat oven to 400°F/200°C, combination steam setting. If your oven has variable steam settings, choose 50%. If not, don’t worry! Just select combi steam at the correct temperature and the oven will work out the humidity for you. Lightly grease the inside of 6 x 12oz/1½ cup ramekins or an 8 cup baking dish or casserole. Set aside.

Step 3

Heat the butter in a saucepan over medium heat. Add the leek and cook, stirring often, until very soft, about 5 minutes.

Step 4

Add the flour to the pan and cook for a further 2 minutes, stirring constantly.

Step 5

Whisk in the chicken stock and milk, a little at a time. Whisk well after each addition, until the mixture smooths out. It’ll be very thick to start with, but will loosen as you add more liquid. When all the liquid has been added, bring to a boil over medium heat, stirring constantly. Simmer until the mixture thickens enough to coat the back of a spoon, then remove from heat. Stir in turkey, then fold through the roasted vegetables. Add salt and pepper to taste.

Step 6

Fill the prepared ramekins or large dish with the turkey filling. Lightly beat the egg with a tablespoon of water in a small bowl, and set aside.

Step 7

Cover the top of the dish/es with the puff pastry. It should hang ⅜ inch (1cm) over the edges of whatever you’re cooking in, to allow for a good lid which covers the entire top of the pie. Trim any excess with a sharp knife. Cut a decorative shape for the top of each pie from any pastry scraps.

Step 8

Brush the pastry all over with egg wash, then cut a few slits in the pastry to allow steam to escape.

Step 9

Put the pie onto a sheet pan in case it bubbles over in the oven, and cook until the filling is bubbling and the pastry is puffed and golden brown, about 30 minutes for individual pies (20 minutes combi steam) or 45 minutes (30 minutes combi steam) for a larger pie. Serve individual pies in their baking dishes. For a large pie, cut through the pastry with a sharp serrated knife to make neat portions, then scoop the filling and pastry onto warmed plates.