Heat 1 tablespoon of the oil in a large, heavy-based saucepan over high heat. Sprinkle the beef with salt and pepper and dust with flour. Cook, in batches, for 3–4 minutes each side or until browned. Remove from the pan and set aside. Heat the remaining oil in the pan. Add the onion, garlic and celery and cook for 5 minutes or until softened. Return the beef to the pan with the bay leaves, tomato paste, vinegar, beer, stock and sugar and bring to the boil. Reduce heat to low, cover with a tight-fitting lid, and cook for 3–3½ hours or until tender. Remove the beef from the cooking liquid and use 2 forks to shred. Discard any fat. Return beef to the pan and mix with the cooking liquid. Allow to cool completely. Preheat oven to 200°C (400°F). To make the pastry, place the butter and water in a saucepan over high heat and bring to the boil. Remove from the heat and stir in the flour and salt until a smooth dough forms. Turn the dough out onto a lightly floured surface and knead until smooth and elastic. Roll the pastry out to 2mm-thick and cut out 4 x 16cm rounds. Line 4 x 9½cm-round lightly greased pie dishes with the pastry. Divide the beef mixture between the pastry cases. Cut out 4 x 12½cm rounds from the remaining pastry and use to top pies. Press the edges to seal and trim the excess pastry. Use a small, sharp knife to cut a slit in the top of the pies. Brush with the egg and cook for 30–35 minutes or until the pastry is cooked through and golden. Makes 4.