Preheat the oven to 150°C.
Brown the lamb shoulder in a roasting tray with oil then rub with garlic and salt.
Add white wine, garlic, and rosemary to the tray and seal tightly with double foil.
Cook for six hours or overnight until tender.
Shred meat from the bone, chill it, and reserve the roasting juices.
Preheat the oven to 180°C.
Layer oil, garlic, sliced potatoes, seasoning, and herbs in a baking dish.
Continue layering with lamb, potatoes, and herbs until ingredients are used.
Pour reserved lamb juices over the torte and cover with foil.
Bake for 90 minutes until potatoes are soft and slice into ten portions to serve.