Slow-Roast Shoulder of Lamb with Onions and Thyme, Balsamic Vinegar

Ingredients (serves 8)

  • 1 shoulder of lamb, about 2.5kg in weight
  • 150ml olive oil
  • 1 bunch fresh thyme
  • 2 garlic bulbs, peeled, plus extra sliced cloves if marinating
  • sea salt and black pepper
  • 8 medium onions, peeled
  • 250ml balsamic vinegar