Peel and cut the carrot into 1.5cm (½") thick coins.
Cut the beef into 2-2.5cm (¾") chunks and season with salt and pepper.
Mix together the flour, dried herbs, salt and pepper in a bowl.
Add half of the oil to a 30cm or 12" frying pan (not nonstick if possible) over a medium heat and fry the carrots and whole onions until they start to get a bit of colour, then transfer to the slow cooker.
Add the remaining oil to the pan and fry the beef until coloured on all sides over a medium-high heat. When browned, add the beef to the slow cooker.
Sprinkle over the flour mixture and stir thoroughly to coat.
Turn the heat under the pan to high and deglaze it with the red wine, and then pour it over the beef.
Mix the beef stock with the tomato paste and red wine vinegar, and pour it into the slow cooker.
Peel the zest from the orange with a vegetable peeler and add it to the slow cooker.
Bash the garlic cloves with the side of a knife, then add them to the slow cooker.
Finally, throw in the prunes and bay leaf and stir well. Have a taste of the sauce and add more salt if required.
Cook on low for 6 hours or on high for 4 hours.
Remove the solids from the crockpot and pick out the beef, prunes, shallots, and carrots and set aside; then discard the remaining solids.
Heat a frying pan over a high heat and pass the cooking juices through a fine-mesh sieve and reduce by 25-30%.
Return the beef and vegetables to the sauce, bring them back to temperature and serve.