Preheat oven to 220°C/428°F.

Dice up your chicken thighs into chunks, season with salt and pepper. Brown them off in an ovenproof frying pan that you will be cooking your pie in. Remove the chicken from the pan and set aside.

Finely slice the leeks and cut the mushrooms into quarters. Melt a knob of butter in the pan. Add the leeks and cook for 3 minutes until wilted. Whack in the mushrooms with a pinch of salt and fry until soft. Sprinkle in the flour.

Give everything a good mix. Cook for a minute. Pour in the cider. Bubble away for a minute.

Add the cream and mustard. Stir the sauce until combined. Add the chicken again, with 3/4 of the parsley. Season with salt and pepper. Remove from the heat.

Melt the second knob of butter and use it to brush over 6 filo sheets. Crumple the pastry with your hands and place on top of the pie filling. Once the whole filling is covered transfer to the oven.

Cook for 20 minutes or until the pastry is golden brown.

Sprinkle over the remaining parsley and serve with mustard.