Pre-heat oven to 200C
Rub lamb all over with olive oil, salt, pepper, and mixed dried herbs
Slice garlic bulbs in half with skin on and slice onions in half with skin on
Place lamb, garlic, and onions in oven for 30 minutes
Remove from oven and add 500ml of stock
Cover tightly with foil and reduce oven temperature to 150C
Cook for 3.5 hours
Remove from oven and remove foil
Slice lemons in half, squeeze lemon juice over lamb and add lemon skins to pan
Cook uncovered for a final 30 minutes
Remove from oven, shred and serve
