Remove the meat from the refrigerator and remove the packaging. Wipe with paper towel and leave to come to room temperature for 30 minutes.
Preheat the oven to 160 C / 325 F / 140 FAN / Gas 2.5.
Peel and roughly chop the carrots, onion and celery.
Peel and finely chop the garlic.
Season the beef with the salt and pepper.
Put the oil in the frying pan over a high heat, then sear the beef on all sides.
Remove the beef and set aside on a plate.
Reduce the heat to medium and add the carrots, celery and onions for about 5 minutes stirring regularly, then add the garlic for 1 minute.
Add a glug of wine to the pan to loosen any bits stuck to the bottom and stir in, then add the remaining wine and stock and bring to a simmer.
Use a slotted spoon to remove the vegetables and place in the bottom of the casserole dish.
Place the meat on top of the vegetables and pour over the liquid. Add the herbs.
Place the lid on and transfer to the oven and cook for 4 hours until tender, rotating the meat each hour. After about 3 hours, the meat will be tender and easily sliceable and after 4 hours you will be able to shred with a fork.
Remove the pot from the oven and with tongs, set the beef onto a cutting board, covering with foil to rest.
Remove any excess fat from the stock, along with the herbs and discard.
Add the cornflour and use a stick blender to combine until smooth.
Put the pot on the hob over a medium heat and stir until thickened
Serve the meat by pulling into chunks with forks or slicing.
Serve the gravy over the meat or leave guests to help themselves.
Alternatively, arrange the vegetables on a serving plate with the meat in top and serve at the table.