Easy chicken and broccoli pie

Method

1. Heat the oven to 200°C/180°C fan/gas 6. In a large deep frying pan, melt the butter and fry the onion for 5 minutes, then add the chicken. Fry for a few minutes, then add the mustard and broccoli. Gently cook for 5 minutes until starting to soften. Add the white sauce to the pan and bring to a simmer to warm through.
2. Turn off the heat, stir in the lemon zest, juice and parsley, then season to taste. Pour the filling into the pie dish and leave to cool for 5 minutes.
3. Unroll the pastry and slice 1cm strips off the edges. Press the strips onto the rim of the dish, brush with beaten egg, then top with the sheet of pastry. Trim off the excess, then cut out shapes for decoration if you like (attach them with more egg). Use a fork to seal/crimp the edges of the pie, brush with beaten egg and bake for 25-30 minutes until the top is golden and the filling is piping hot.