In a small bowl, combine all the dry rub ingredients, and then lightly coat the brisket in olive oil and generously season on both sides with the rub.
Tightly roll up the brisket letting it rest seam-side down to keep it closed and tie about 6 pieces of butcher’s string around the roll to secure it.
Place a large, deep baking tray onto your stove top and turn the burners/plates under the tray on to a medium-high heat. Add a big splash of olive oil to the baking tray and evenly brown the brisket on all its sides, including the ends, to seal the meat and lock in the juices.
Pour the beef stock into the baking tray, tightly cover the tray with a double layer of tinfoil and roast the brisket for 4 hours. Spoon the stock over the meat every hour and remove the tinfoil in the last 30 minutes of cooking.
Add all the root vegetables to a separate oven dish, drizzle with olive oil, toss to ensure they are evenly coated and season with salt and pepper. In the last hour of the beef’s cooking time, place the vegetables in the oven on a shelf below the roast and cook for 1 hour.
Remove the roast from the oven and transfer to a chopping board. Loosely cover with tinfoil and let it rest for 15 minutes.
Increase the temperature to 200°C/390°F and continue to roast the vegetables whilst the meat rests so the potatoes can become crispy and golden.
In the meanwhile, pour the beef drippings from the roast’s baking tray into a small saucepan and slowly whisk in the flour over a medium heat. Cook the gravy uncovered for 5 minutes or until it thickens. Season with salt and pepper to taste.
Carve the succulent, slow-cooked brisket into thick slices, plate alongside the colourful roasted root vegetables and generously drizzle with hot gravy.