Get a pan hot with the oil, season the beef and brown it well all over to build colour, then lift it out and set aside. Drop the heat slightly and add the butter, then cook the onion until soft and starting to turn sweet before stirring in the garlic. Add the fresh thyme sprigs and let them cook with the onions for a minute to release their flavour.

Add the tomato purée and cook it out for a minute, then stir in the flour and cook for a couple of minutes to form a base.

Pour in the Worcestershire sauce followed by the beef stock gradually, stirring as you go so it stays smooth and thick. Add the English mustard, return the beef and let it simmer gently for 1½ to 2 hours until the beef is tender.

At the end of the cook, check the consistency of the sauce. You’re looking for a thick gravy that coats the beef. If it’s too thin, let it reduce a little more. If it’s too thick, loosen it with a splash of water, especially as you’ll want to reserve some for dipping.

Add a good amount of cracked black pepper, then spoon off a couple of ladles of the gravy into a separate pan and set aside for dipping later. Remove the thyme stalks, then let the beef filling cool completely so it doesn’t melt the pastry when assembling.

Lay out the puff pastry sheets and cut each into 4 rectangles so you have 8 pieces. Spoon a generous amount of the beef mixture onto 4 of them, then top with the remaining 4 pieces to form the bakes. Crimp the edges, brush with egg wash and lightly score the tops.

Bake at 200°C for 20–25 minutes until golden and crisp.

While they bake, bring the reserved gravy back to a simmer, reduce slightly if needed and finish with an extra splash of Worcestershire sauce and a knob of butter for a glossy finish.

Serve the steak bakes hot with the rich gravy on the side for dipping.