Add the cold butter and shortening to the flour and rub together until well mixed. Stir in the salt and thyme

Add 3 tablespoons of ice water, and stir in. If necessary, add further water a teaspoon at a time until the dough just comes together, but is not sticky. Wrap the dough in clingfilm and place in the fridge for 30 minutes

Pre-heat the oven to 190°C / 375°F / Gas Mark 5

Melt the butter in a large non-stick pan and add in the onions. Cook until they start to soften and turn translucent

Add in the garlic, thyme and mushrooms. Cook for a few more minutes until the mushrooms start to wilt

Add the salt and the flour, and stir well. Continue to cook until no dry flour is visible, then add in the wine and the stock. Simmer until the mixture thickens

Stir through the cream, then add in the cooked chicken. Put to one side while you roll out the pastry

Lightly grease and flour a 23cm pie dish. Divide the pastry into 1/3 and 2/3. Roll the larger piece in to a circle, a few millimetres thick, and line the pie dish

Put the pie filling into the pastry lined dish, then roll out the remaining pastry to form the lid. Brush the edges of the base layer of pastry with a little egg wash, then press and pinch the edges of the lid to form a seal

Brush the top of the crust with more of the egg wash, then cut two slits on the top

Bake the pie for 40 minutes, then serve with a cream mash and some veg