Beef, ale and mushroom pie

This is not a meal that I would normally do in the middle of summer. However today it's my dad's birthday and I was cooking him lunch and this is one of his favourites. Afterwards Steve said it was the tastiest pie he has ever eaten. The recipe is from Olive magazine a couple of months ago. 

Ingredients 
Serves 6 
1.5kg braising steak or stewing steak, trimmed and cut into chunks 
3 onions cut into thin wedges (I just used one large one)
2 garlic cloves crushed 
2 sprigs of fresh Thyme (I used dried)
500g mushrooms 
400ml dark ale 
500g shortcrust pastry (I used a ready made one, which was 375g) 
Olive oil 
Salt and pepper 
1 egg beaten

Method
Heat the oven to 170c Heat the oil in a large casserole dish, fry the meat in batches until browned. Remove the meat from the pan. Fry the onions until golden, remove the onions from the pan, and add the mushrooms to cook slightly. Put everything back into the casserole dish, add the thyme, garlic and flour and stir. Gradually add the dark ale, and bring to a simmer. Season. Cover and cook for 2 hours until the meat is tender. Take out of the oven and leave the cool. Turn up the oven to 190C. Put the meat into a pie dish, cover with the pastry. Decorate the top with any leftover trimmings, then brush with a beaten egg. Cook in the oven for 30-40 mins, until crisp and golden.