Toss the beef in flour seasoned well with salt, pepper and a big pinch allspice.
Heat up a thick metal casserole (with a well fitting lid), put a spoonful of beef dripping (or alternatively use oil) and fry meat, browning it well. Remove from pan and add vegetables. Cook for five minutes then add garlic, beer, Worcester sauce, dried mushrooms, beef and stock (scraping any residue from the base of the pan). Put in the bay and thyme and bring to a simmer, cover and put in the oven at 120°C for one and a half hours.
Season kidneys and stir into beef mixture and put back into the oven for another half hour.
Check that beef is tender but not falling apart; if not cook for another half hour or until done.
Remove from oven and strain casserole and reduce liquid by half over a high flame. Check seasoning and add more salt if necessary and some fresh ground black pepper. Cool the mixture.
Roll out puff pastry on a well floured surface and line six individual pie tins or one large tin, leaving some to overlap the edge. Pour filling into pie and egg wash rim. Place lid on top and seal edges with a fork then trim the edges with a knife.
Brush with beaten egg and pierce centres to allow steam to escape.
Cook in a preheated oven (175°C) for 35 minutes individually or slightly longer for one large pie.