Pre-heat oven to 200C.
Rub the lamb all over with olive oil, salt, pepper, and mixed dried herbs.
Place the garlic and onions in the oven for 30 minutes.
Remove from the oven and add 500ml of stock, cover tightly with foil, and reduce oven temperature to 150C. Cook for 3.5 hours.
Remove from the oven, remove the foil, and add the lemon halves, squeezing the juice over the lamb and throwing in the skins.
Cook for a final 30 minutes uncovered.
Remove from the oven, shred the lamb, and enjoy!