Preheat the oven to 325°F Heat the oil in a large casserole, add the lamb in batches and brown off well. Set the lamb aside.
Return the pan to the heat and add the onions, carrots and celery. Cover and cook for 10 mins until the vegetables are starting to soften. Then add the garlic and cinnamon and cook for a further 2 minutes
Add rosemary, tomatoes, white wine and season well with sea salt and black pepper. Cover and cook in the preheated oven for 1 1/2 hrs, until the lamb is tender.
Stir in the olives and mint and crumble over the feta cheese to serve.