Sear the Beef: Pat the beef joint dry with kitchen paper and season it generously all over with salt and pepper. Heat the olive oil in a large, heavy-bottomed pot or Dutch oven over a medium-high heat. Carefully place the beef in the pot and sear for 3-4 minutes on each side, until a deep brown crust has formed. Remove the beef and set it aside on a plate.

Sauté the Aromatics: Reduce the heat to medium. Add the sliced onions to the same pot, scraping up any browned bits from the bottom. Cook for 8-10 minutes, stirring occasionally, until the onions are soft and have started to caramelise. Add the minced garlic and cook for another minute until fragrant.

Deglaze and Build the Jus: If using, pour in the red wine to deglaze the pot. Let it bubble away for 2-3 minutes, scraping the bottom of the pot with a wooden spoon to release all the flavourful residue. Pour in the beef stock, Worcestershire sauce, and soy sauce. Add the thyme sprigs and bay leaf.

Simmer the Beef: Return the seared beef joint to the pot. The liquid should come about halfway up the side of the meat. Bring it to a gentle simmer, then reduce the heat to low, cover the pot, and let it cook for 2 to 2.5 hours, or until the beef is very tender.

Rest and Slice: Carefully remove the beef from the pot and place it on a cutting board. Cover it loosely with foil and let it rest for at least 15 minutes. This is a crucial step for juicy meat. While it rests, strain the jus through a fine-mesh sieve into a clean saucepan, discarding the onions and herbs. Keep the jus warm over a low heat.

Slice the Beef: Once rested, use a sharp knife to slice the beef as thinly as you possibly can, cutting against the grain. I find that a long carving knife gives the best results here for uniform slices.

Prepare the Bread: Preheat your grill to a medium-high setting. Spread the softened butter on the cut sides of your baguettes and place them under the grill for 1-2 minutes, until lightly toasted and golden.

Assemble the Sandwiches: Pile the thinly sliced beef generously onto the bottom half of each baguette. Top with 2-3 slices of Provolone or Gruyère cheese.

Melt the Cheese: Place the open-faced sandwiches back under the grill for 2-3 minutes, just until the cheese is completely melted, bubbling, and starting to turn golden at the edges.

Serve Immediately: Place the top half of the baguette on, slice the sandwiches in half if desired, and serve immediately with a small bowl of the hot jus for dipping.