Classic British Steak and Mushroom Pie

Heat the olive oil in a large flameproof casserole or deep skillet over medium-high heat. Toss the beef chunks in the seasoned flour, shaking off any excess. Brown the beef in batches until deeply coloured on all sides. You want a good crust here—that's where the flavour lives. Set the beef aside.

Turn the heat down to medium. Add the chopped onion and cook for 5-6 minutes until softened and translucent. Add the garlic and cook for another minute, until fragrant.

Tip the sliced mushrooms into the pan. Cook for 5-6 minutes, stirring now and then, until the mushrooms release their liquid and start to brown. That's where the umami kicks in.

Stir in the tomato puree and Worcestershire sauce, scraping up any sticky bits from the bottom of the pan. Pour in the beef stock, add the thyme and bay leaves, and bring to a gentle simmer.

Return the beef to the pan along with any juices. Season with salt and pepper, then cover and simmer very gently for about 1.5 hours, or until the beef is tender and the sauce is rich and thickened. Give it a stir every now and again to make sure it doesn't catch.

Once the beef is lovely and tender, taste and adjust the seasoning. Remove the bay leaves, then let the filling cool completely. You can speed this up by tipping it into a wide dish and popping it in the fridge.

Preheat your oven to 200°C (400°F). Roll out the puff pastry on a lightly floured surface so it's a little bigger than your pie dish—you want a good overhang for a nice crimped edge.

Spoon the cooled filling into a pie dish (roughly 23cm/9inch). Brush the rim of the dish with a little water or egg wash, then drape the pastry over the top. Press to seal, then trim any excess. Crimp the edges with a fork, and cut a small steam hole in the centre.

Brush the pastry all over with the beaten egg. Bake for 30-35 minutes, until the pastry is puffed up and deep golden brown. Leave to stand for 5 minutes before serving.