1. Preheat oven 150°C, gas mark 2. Warm the oil in a large ovenproof casserole pan over a high heat. Season the beef and add to the pan, in batches if necessary, and cook for 5 minutes, turning often, until well browned. Remove from the pan and set aside.
2. Reduce the heat to low, then add the onion, celery and carrot to the pan. Cook gently for 5 minutes with the lid on the pan, until softened.
3. Increase the heat to high. Return the beef to the pan, pour over the red wine, stock and tomatoes. Bring to a simmer, then cover and place into the oven for 2½ hours. Remove from the oven, stir in the barley, cover and return to the oven for a further 30 minutes, until meat is tender and falling apart.
4. Meanwhile make the gremolata. Finely chop the herbs and garlic, add the zest and season. Serve the beef sprinkled with the gremolata over the top. Great served with mashed potato.