In a large non-stick saucepan, melt the butter and sauté the onion for 6-7 minutes, until very soft. In the meantime, place the flour in a large bowl and season with pepper.
Toss the meat pieces in the flour or lightly coat, then add the meat to the frying pan with the onions.
Fry the meat in the butter until the meat is sealed and a light golden colour.
Add the Sarson’s Worcester sauce, red wine and mushrooms and cook for 1 minute. Mix in 400ml boiling water and bring to the boil, then simmer for 1 hour, stirring regularly. Allow to cool.
Cut out four circles (17cm in diameter) of baking paper. On a clean surface, dusted with flour, roll the pastry out until around ½cm thick. Cut four 16cm in diameter circles out of the pastry, and place each on a prepared circle of baking paper. Cut out four 10cm pastry circles for the pie lids.
Spoon a quarter of the meat mixture into the middle of one of the large pastry circles, then pinch the pastry up around the mixture to secure, holding it in place with the baking paper. Top with the pastry lid and pinch the edges together to fix, folding over to make a rim and secure in place.
Tie a piece of kitchen string around the baking paper to keep the paper in place, and then prick the top of the pie with a fork. Place on a baking tray and repeat the process to make four pies.
Brush the tops of the pies with the egg wash, than bake for 20 minutes, or until golden.
Tip: Serve with broccoli, mashed potato and gravy.