Season beef with salt and pepper, and leave to sit for 20 minutes. I put this in a colander over a bowl to let the salt draw out the moisture. This liquid can be added to the strew later (once you add the stock). In the meantime, coarsely chop the onion and saute in a large pot with some oil until the onion is browned. Remove the onion from the pot and leave aside.

Brown the beef in batches, setting cooked beef to the side. Do not worry about fully cooking the beef at this step.

Add 1 tbsp of butter to the pot over a low heat. Return onion and beef to the pot, add the flour and stir until combined. Cook for a minute or two to cook the raw flour taste out.

Increase heat to medium-high and add wine (or water) and scrap any pieces of meat stuck to the bottom of the pan. Reduce the wine by half and then add beef stock, thyme, worcestershire sauce and strained liquid from the beef if using.

Pressure cooker: Cook on high for 30 minutes with a 15 minute natural release. On the hob: add an extra 200ml of water and simmer with the lid on for 1.5 hours adding a little more water if it ever gets too dry. 

[Optional step] Wait for the beef and gravy to cool down and chill covered in the fridge overnight. This improves the flavour of the beef as it absorbs the gravy and also helps it to thicken.

Set the oven to 180C. Using a slotted spoon, remove the beef from the stew and put into a baking dish. Simmer the gravy to reduce it to a thicker consistency (if you used the pressure cooker you may need to simmer for longer). You can also thicken it by mixing some stock in another bowl with some flour and adding back into the stew. Add enough gravy to cover the meat in the baking dish.

Roll out puff pastry to ~1cm thickness and slightly larger than the size of your dish. Trim off the ends to make a square. These off-cuts are great to use for making nutella pastry twists and can be stored in the fridge to avoid food waste.

Lay the pastry over the dish, tucking excess pastry back in on itself. The pastry will sag a little in the middle but this is okay.  Add a couple of steam vents and bake at 180C for 30 minutes until golden brown. [Optional] Adding an egg wash to the pastry before baking can create a glossy, more visually appealing finish. However, it does not really change the flavour so it feels like a needless waste of an egg. The steak pie will be just as delicious without it.

Remove the pie from the oven, cut into 4 slices and serve with mashed potatoes and vegetables. Pour over any excess gravy over the vegetables.