2) Preheat the oven to 150C/Gas 2. Heat the oil in a casserole dish with a lid. Drain the beef from any remaining marinade and pat dry with kitchen paper. Add to the heated pan and cook for 3 to 4 minutes until browned on all sides.
3) Remove the beef from the pan with a slotted spoon and set aside in a bowl. Add the shallots, garlic, thyme and bay leaves to the pan and cook for 3 to 4 minutes until shallots have softened but not coloured. Stir in the flour and cook for a minute or so, scraping the bottom of the pan with a wooden spoon to remove any sediment.
4) Stir the tomato puree into the pan with the remaining stout and the chicken stock and then bring to a simmer. Return the beef to the pan with the barley and season generously.
5) Cover with a lid and place in the oven for 1 1/2 hours, then add the celeriac, carrots and parsnip and return to the oven for another 40 minutes to 1 hour until the beef and root vegetables are very tender but still holding their shape.
6) Remove from the oven and garnish with the thyme leaves and bay leaves. Place straight on to the table and allow everyone to help themselves. Have plenty of brown soda bread around to mop up all of those delicious juices.