||Preheat the oven to 170ºc. Place a heavy based casserole over a moderately high heat. Toss the beef in the flour, coat well and shake to remove any excess. Fry the beef in the oil in 2 batches, for 6-8 minutes or until well coloured.
||Turn the heat down to medium and place all of the meat back into the casserole. Add the onion, mushrooms and bay leaf and stir with the meat for 2 minutes or until the vegetables are lightly coloured. Add the stock and bring up to the boil.
||Cover and place in the oven for 2 hours or until the meat is very tender. If you want the sauce a little thicker you can place it over a high heat to reduce slightly. Add the vinegar and season with salt and pepper. Transfer to a large pie dish and allow to cool thoroughly. You can refrigerate for up to 2 days.
||Preheat the oven to 220ºc. Roll the pastry into a piece a little larger than the pie dish. Place over the cooled meat mixture and gently tuck in the sides. Brush with the beaten egg and cute a few slits in the pastry to allow the steam to escape.
||Bake for 20-25 minutes or until the pastry is golden brown and the filling is bubbling. Serve with mashed potato and steamed greens.