Prepare the beef: Pat the chuck roast dry with kitchen paper. Season generously on all sides with salt and pepper. You'll hear a satisfying sizzle when it hits the hot pan in the next step.

Sear the meat: Heat the olive oil in a large frying pan over medium-high heat until it shimmers. Place the beef in the pan and leave it undisturbed for 3-4 minutes. You'll see a deep brown crust forming on the bottom — that's the flavour. Flip and repeat on all sides. The kitchen will smell richly of browned beef.

Sauté the aromatics: Remove the beef to a plate. Add the sliced onions to the same pan and cook for 3-4 minutes, stirring occasionally, until they turn translucent and the edges begin to brown. Add the minced garlic and cook for 30 seconds until fragrant.

Build the braising liquid: Pour in about 100ml of the beef stock and scrape the bottom of the pan with a wooden spoon to lift all those browned bits. This is called deglazing, and it's where so much of the savoury depth comes from. Let it bubble for a minute, then stir in the tomato purée, Worcestershire sauce, dried thyme, and the remaining beef stock.

Assemble in the slow cooker: Place the carrots and baby potatoes in the bottom of your slow cooker. Lay the seared beef on top. Pour the onion and stock mixture over the meat, and tuck the bay leaves in on the sides. The liquid should come about halfway up the meat — if it looks low, add a splash more stock.

Cook low and slow: Cover and cook on LOW for 8 hours or on HIGH for 5 hours. After 6 hours on low, the beef should be fork-tender — you'll be able to pull it apart with minimal resistance. The carrots will be soft but not mushy, and the potatoes will have absorbed the savoury broth.

Thicken the gravy (optional): Carefully remove the beef and vegetables to a serving platter and cover loosely with foil. Strain the cooking liquid into a saucepan, discarding the bay leaves. Bring to a simmer over medium heat, then whisk in the cornflour slurry. Cook for 2-3 minutes, stirring constantly, until the gravy thickens to a glossy, pourable consistency. You'll see it coat the back of a spoon.

Rest and serve: Let the beef rest for 5-10 minutes before slicing against the grain into thick pieces. Spoon the gravy over the meat and vegetables. The beef should be so tender it almost falls apart as you slice it.