Throw the beef in a saucepan with some oil and start browning it. While this is happening, chop the onions and carrots.
When the beef is nicely browned, pour in about half the bottle of ale and an equal quantity of water. Bring to a bubble.
When the onions and carrots are chopped, put them in a frying pan with some oil to soften. When they're done, add them to the saucepan.
Add some more ale and water, along with salt, pepper, and the stock cubes. The sauce should be quite runny and should cover the other contents of the pan. Leave to bubble for as long as possible. (An hour is good.)
Meanwhile, prepare the pie dish. If necessary, roll out the pastry (remember to flour the work surface first). Line the inside of the dish with pastry and seal the joins.
When the stew is ready, add the flour to thicken it, then pour it into the pie dish. Add the pastry lid and seal the pie. Make some holes in the lid and put the dish in the oven.