In a large frypan, heat the olive oil over a medium-high heat. Season the brisket with the salt and pepper on both sides, and add to the fry pan. Sear until browned on all sides, about 2-3 minutes each side and remove from the heat.

Meanwhile, place the brown onion, garlic, carrots, thyme, rosemary and bay leaves into the slow cooker. Place the meat on top of the ingredients along with any remaining oil from the pan. Pour over the water, ensuring the beef brisket is just covered.

Cook for 6-8 hours until the meat is tender. When it is cooked, remove from the slow cooker and slice on a chopping board. Remove the carrots from the slow cooker and set aside.

Pour the juices from the slow cooker into a fry pan on a high heat and cook, stirring frequently, until the sauce has reduced, about 5 minutes.

Serve the beef with the sauce poured over the top, a side of carrots and some green vegetables or roasted potatoes.