Method

• 1.
  Preheat oven to 100°C. Place a sheet of foil large enough to enclose short rib on a work surface. Make a bed with thyme, rosemary and garlic in the centre of the foil. Place short rib on top, drizzle with 2 tbs oil and season. Wrap in foil, then wrap parcel in another sheet of foil to enclose securely. Place in a roasting pan with 2 cups (500ml) water, cover with foil and bake for 8 hours or until soft and tender. Remove from oven.

• 2.
  Increase oven to 230°C. Carefully remove parcel from casserole. Discard foil and herbs, and reserve short rib and garlic separately. Reserve cooking juices in casserole and stand for 10-15 minutes for impurities to rise to the surface, then skim surface and discard. Stir in the vinegar, soy sauce and mustard, then return short rib to casserole and baste with liquid. Return to oven and cook, uncovered, basting every 5 minutes, for 20 minutes or until glazed. Remove from oven and cover to keep warm.
• 3.
  Cook onions in a saucepan of boiling water for 8-10 minutes until tender. Drain, then refresh in cold water and peel.
• 4.
  Heat remaining 2 tbs oil in a frypan over medium-low heat. Add onions and cook, shaking pan, for 6-8 minutes until golden. Add cavolo nero and cook, turning, for 3-4 minutes until wilted. Season.
• 5.
  Serve short rib with cavolo nero, onion, reserved garlic and any resting juices.