Preheat the oven to 200C/400F/Gasoline 6.
Heat the oil in a deep frying pan and fry the beef mince for 4-5 minutes, breaking it up with a wooden spoon as it browns.
Add the onion and cook for 2-3 minutes, then sprint in the tomato purée and cook for 2-3 more minutes. Dash in the flour and cook for a extra minute, then add the chopped mushrooms, the substantial or beef stock and a couple of dashes of Worcestershire sauce. Carry to the boil, then lower the heat, conceal the pan with a lid and toddle away to simmer for 20 minutes. Station apart and toddle away to chilly, then flip the meat combination into a one litre pie dish.
Roll out the pastry on a floured work floor except it’s far a cramped bit higher than the pie dish. Gently drape the pastry over the dish, pressing firmly onto the sides. Neatly-organized, then form the sides into a fluted form.
Reduce aid some leaf shapes out of the pastry trimmings and beautify the head of the pie, sticking them to the pastry with the overwhelmed egg yolk.
Salvage three or four slits in the pastry to allow the steam to flee, then brush the pie with the rest of the overwhelmed egg yolk and bake in the oven for 20-25 minutes, or except golden-brown.
To aid, nick into wedges.