Preheat the oven to 160°C/325°F/Gas mark 3. Heat half the oil in a large casserole dish with a lid, over a high heat. Add the housekeepers cut and fry for 3-4 minutes, until lightly browned on all sides, turning regularly. Transfer to a plate and set aside. Add the carrots, baby onions and garlic to the pan and sauté for about 5 minutes, until lightly golden. Tip into a bowl and set aside.
Return the housekeepers cut to the casserole with the herbs and barley. Pour over the stock and wine to cover and return to the boil. Season to taste and cover tightly first with foil and then the lid. Bake for 1½ hours. Remove the casserole from the oven. Add the reserved vegetables and cook for another hour, until the meat is very tender and almost falling apart.
Lift the meat out of the casserole and leave to cool. Remove the string and wrap tightly in tin foil. Place in fridge for three to four hours, or overnight if possible, as this helps the beef to keep its shape. Leave the cooking juices to cool, then cover with a lid and chill until needed.
Once chilled, you can skim off all the solidified fat and strain the vegetables through a colander over a pan, reserving the vegetables. Bring the liquid to the boil, then reduce to a simmer and cook for 40-45 minutes until reduced by half, skimming off any impurities that rise to the surface. Return the vegetables to the sauce and simmer for about 5 minutes until warmed through. Season to taste.
Remove foil from the beef and trim off the ends to neaten. Slice into eight pieces, each about 2.5 cm thick. Heat the rest of the oil in a frying pan and very gently sear the beef for 3-4 minutes on each side, until golden brown and warmed through. Drain on kitchen paper. Spoon the champ into warmed bowls and arrange a piece of beef on top of each one. Spoon over the vegetables and sauce, then garnish with parsley to serve.