Cut the casserole steak into cubes and roll in seasoned flour. (plain flour with some salt and pepper). Shake off the excess.
Add the steak, onion, mushrooms and carrot to a casserole dish and pour the whole bottle of beer over them. Add the stock cube, a little bit of water and add some salt and pepper.
Cook on a low heat for as long as possible; approximately 3-4 hours.
Half an hour before the end of the cooking add a couple of tablespoons of flour to the casserole dish; mix well. Turn the heat up to about 200 degrees C.
Cook the flour into the casserole dish for about 20 minutes, then take out of the oven and leave to cool. I pour the whole thing into a new, flat, baking dish so that the surface area is increased and it cools faster.
Once the meat and vegetables are cooled it should have a really thick gravy and pretty much need spooning out of the dish.
Make the shortcrust pastry. Sieve the plain flour into a large mixing bowl. Cut up the butter into small pieces and put into the bowl with a pinch of salt. Rub the butter into the flour using your fingers (you can use a food processor but I prefer it done ‘traditionally’). When it looks like breadcrumbs stir cold water in tablespoon by tablespoon using a knife. It should start coming together as dough. Knead the pastry until it’s smooth and put it in the fridge for at least half an hour to rest.
Line a big pie dish or the lid of your biggest pyrex dish with the shortcrust pastry.
Spoon the cold steak mixture into the pie dish and roll out the top. Paint the edges of the pie with milk or beaten egg to make it ‘sticky’ and then stick the top to it.
Crimp the edges with your fingers then cut a couple of vents in the top and decorate with pastry leaves (if you want to).
Bake in an oven at 180 degrees C for 30 minutes or until the pastry is brown and pie centre is hot. Serve.