Heat the oil in a frying pan and cook the garlic and onions for 5-6 mins to soften, then add the butter. Once the butter is foaming, add the mushrooms and cook for 5-8 mins until softened and any liquid has evaporated. Season well, then tip onto a plate.

Tip the plain flour into a bowl with a good pinch of salt and pepper. Toss the sliced steak in the seasoned flour. Put the pan back on the heat, adding a little more oil if necessary, then fry the steak for 3-4 mins over a high heat until just browned. Add the mushrooms back to the pan. Pour in the stock, reduce the heat to medium and cook for 5 mins, until bubbling. Stir in the crème fraîche and chopped parsley, if using.

Heat the oven to 220C/200C fan/gas 7. Tip the steak mix into a 15cm x 25cm shallow pie dish. Unroll the pastry over the dish and press it down along the rim and down the sides – wet the rim and sides to help it stick if necessary. Trim off any excess pastry, leaving a border down the side to help the lid stay in place. Cut two small slits in the top of the pie and use any offcuts to decorate the top if you like. Brush the pastry with the egg, then bake for 40 mins, or until the pastry is golden and puffed up.