Preheat oven to 180°C/350F/Gas Mark 4.
Line a baking tray with parchment paper and set aside. Roll the pastry if needed and transfer in the fridge covered until required.
Meanwhile, heat the oil in a frying pan over medium heat. add the beef pieces and sear for 2 minutes. Add the onion, carrots, and garlic and cook for a further 3 minutes or until lightly coloured.
Add the stock, red wine and mustard and Worcestershire sauce. Simmer for 1.30 hours or until cooked through.
Using 2 forks, pull the meat to create a pulled beef texture.
Check the seasoning and add extra herbs if needed. Sert aside to cool.
Once cool enough, take the puff pastry out from the fridge and draw 2 circles depending on serving preference. For individual portions, draw 1 smaller 6cm diameter and an top circle of 8 cm or so. The top circle needs to be wider to allow the filing to be covered. For a pie to share ensure the top circle is widder than the base and that it will fit your baking tray.
Place the smaller circles on the baking tray and brush with egg wash. Spoon enough of the beef mixture on the pastry and cover with the second larger pastry circle.
Decorate slightly the top and brush again with egg wash. Create a small opening or chimney to allow excess steam to escape and allow the pastry to bake well.
Remove excess pastry on the edges too if needed.
Place in the oven and bake for 25-35 minutes depending on size until ready to serve.
Serve warm or at room temperature with some salad leaves.
