Heat the oil in a medium pot then add the onion and garlic. Cook while stirring until the onion is soft.
Add the beef while stirring to break up any lumps. It will take about 10 minutes for the beef to cook through.
Sprinkle the flour over the meat, then cook for 1 minute, this should act as a thickener making the mixture become dry and crumbly.
Add the ketchup, Worcestershire sauce, beef stock, and stock cube. Simmer while stirring for about 10 minutes until the sauce is thick. Season with salt and pepper then remove from the heat and cool completely.
To Assemble
Preheat the camp oven to 400 degrees F (200 degrees C). Grease the baking dish you choose (pie tin, pie plate, pie tray, or muffin tin).
Line the base of each pie with the shortcrust pastry.
Fill the pie with the filling.
Brush around the edge of each pie with the egg, top each pie with the puff pastry, crimping the edges together to seal.
Brush the top of each pie with the whisked egg. This helps create a golden brown color to the pie,
Bake the pies in the camp oven for 10 minutes, then reduce the temperature down to 350 degrees F (180 degrees C) and cook for an additional 15 minutes or until the pastry is puffed and golden brown. The cook time may vary based on the size of the pie you create.