One-pot comfort: Chicken pie with winter veggies

Preheat the oven to 400˚F.

Melt the butter in a 12-inch heavy large cast-iron frying pan or other ovenproof pan over medium heat. Add the onion, celery, carrots, parsnips, turnip, and garlic and cook, stirring occasionally, for 10 minutes, or until the root vegetables are almost tender. Sprinkle in the flour and stir well for 1 minute to cook the flour without browning. Raise the heat to medium-high and stir in the broth, followed by ¾ cup of the milk, the cream, and the thyme. Bring to a simmer. Reduce the heat to medium-low and simmer gently, stirring occasionally, for about 5 minutes, or until the vegetables are tender. Remove from the heat and stir in the chicken and season with salt and pepper. Cool slightly. Remove the thyme stems.

In a small bowl, mix the egg and remaining 1 tablespoon of milk with a fork to combine. Roll out the pastry on a lightly floured work surface into a 13-inch square. Brush the egg mixture around the edge of the pan. Lay the pastry over the pan and gently press the hanging edges of pastry to adhere to the sides of the pan. Brush some of the egg mixture over the pastry. Transfer to the oven and bake for about 30 minutes, or until the topping is deep golden brown. Cool slightly and serve.