Place the steak and kidney in a freezer bag with the flour, salt and pepper.
Shake the bag to coat the meat evenly in the seasoned flour.
Shake off the excess.
In a large heavy-based saucepan, heat the oil.
Fry the onions to soften. This should take about 10 minutes.
Then add the meat and cook over medium heat until browned all over.
Add a bit more oil if necessary and take care it doesn’t burn.
Add the seasoning, herbs, Worcestershire sauce and then gradually stir in the water / stock. Add the mushrooms.
Bring to the boil.
Simmer gently on the hob for about 2 hours until the meat is tender, adding a little more liquid if it is getting too dry.
Taste and adjust the seasoning if necessary.
In the meantime make the pastry.
Take the butter hard from the fridge.
Weigh, then wrap the required amount in foil.
Place in the freezer for 30 minutes.
Sift the flour and salt into a large mixing bowl.
Remove the butter from the freezer, hold it in the foil, and then dip it into the flour.
Place a coarse grater in the bowl in the middle of the flour.
Grate the butter into the flour, dipping it into the flour frequently to make grating easier.
Take a palette knife and cut the fat into the flour.
Don’t use you hands at this stage as you need to keep the mixture cold.
Work until the mixture is crumbly.
You then need to add sufficient water to bring the dough together, leaving the sides of the bowl clean. Too much water will make the pastry hard.
Place the pastry in a polythene bag and leave in the fridge for 30 minutes to chill.
Preheat the oven to Gas Mark 7 / 220°C / 200°C fan.
Transfer the cooked meat to a 1 litre / 2 pint pie dish.
On a floured surface and using a floured rolling pin, roll out the pastry to about 2.5 cm / 1” larger than the pie dish. Then cut a further strip all round.
Brush the edge of the pie dish with beaten egg and press the strip on to it.
Brush the strip with more beaten egg and place the pastry lid on top. Press the lid down on the strip to seal it.
Crimp the edge (between thumb and forefinger) all the way round the pie.
Cut a small steam hole in the centre.
Make pastry leaves to decorate the pie and arrange them around the steam hole, sticking them to the lid with beaten egg.
Brush the lid with beaten egg.
Bake for 20 – 25 minutes until the pastry is cooked and golden brown.
Serve immediately with plain boiled or mashed potatoes and steamed leafy green vegetables such as kale or cabbage.