First, for a better result. Caramelised the beef roast. Over high heat, in a sauté pan or casserole pan, drizzle olive oil and add the beef roast. Colour on all sides for 2-3 minutes on each side.
Remove from the heat.
Place all the vegetables and herbs in the slow cooker and season with salt and pepper. Add the caramelized beef roast and the stock. Place the lid and cook on LOW for 8hrs.
Just before serving, in a small bowl, combine the cornflour with cold water.
Gently lift the beef onto a board, cover with foil and allow to rest for 10 minutes. Stir in cornflour mix into the cooking juices and leave to thicken for 5 minutes.
Alternatively, keep the caramelised beef pieces in the casserole dish and add the vegetables.
Over medium/high heat, colour the vegetables for a further 4-5 minutes, stirring to ensure the vegetables don’t attach. Pour over the 800ml of beef stock and cover with a lid. Place in the oven and braise for 1h30 minutes until tender to the fork. Check the texture of the cooking juices and add some of the cornflour mixture if too thin.
Check the seasoning. Carve the beef and serve with vegetables and sauce and some mashed potatoes if desired.