Preheat the oven to 180°C.
Heat the oil / butter over a medium heat and add the chicken and leeks together. Fry for 3-5 minutes, turning the chicken to ensure all sides turn from pink to white.
Add the broccoli, combine everything in the pan together, reduce the heat to low and cover with a lid. Allow to cook for 5-8 minutes - this will allow the broccoli to soften and the chicken to fully cook.
There should be a little moisture in the pan from this part of the cooking process. If not, add around 50ml water and then crumble the stock cube over the mix. Ensure the stock cube is fully combined.
Replace the lid and allow to cook for 2-3 minutes.
Add the mascarpone cheese / soured cream and thyme. Stir to melt this through the dish.
Pour the mix into a pie dish.
Roll your pastry of choice between 2 sheets of greaseproof paper and place this over your pie filling. Bake for 25-30 minutes, until the pastry is golden.
