Soak dried porcini in 1 cup/250ml boiling water for 20 minutes.
Spoon out the porcini mushrooms, roughly chop and keep the liquid for cooking the pie filling.
Heat a large pan or Dutch oven over medium to high heat and add olive oil.
Add the beef when the pan is hot enough and brown well on all sides.
Lower the heat and add the onions, sauté until soft and lightly browned.
Add the carrots, button or chestnut mushrooms, garlic, and sauté for a few more minutes.
Stir in the tomato paste until all combined and cook for a few minutes.
Sprinkle on the flour and stir well together.
Deglaze the pan with the liquid from dried porcini mushrooms then add the beef stock just enough to cover the beef.
Crumble the beef stock cube in and add the thyme, bay leaves, freshly ground black pepper, porcini mushrooms, and the Worcestershire sauce.
Bring the pan to boil and simmer gently on low heat for about 2 to 2.5 hours or until the meat is tender.
When the meat is cooked, you should have some gravy left in the filling thick enough to cover the back of a spoon. If the gravy is too runny, cook it further without the lid and reduce the gravy down to the right consistency.
Check the seasoning and add some salt if needed. Stir in the chopped parsley.
Transfer the filling to an 11" x 7" (27 cm x 19 cm) oval pie dish (or a 10" (25 cm) diameter pie dish), remove the thyme and the bay leaves, and let it cool down to room temperature.