preheat the oven to 180°C. Toss the shanks in the flour. Place half the olive oil in a frying pan over a high heat and cook the meat until browned. Place shanks into large baking dish.
Add the remaining oil to the pan and cook the leeks and garlic until golden. Add wine, chicken stock, lemon rind, thyme and rosemary to the pan. Transfer to the baking dish.
Cover the dish tightly with aluminium foil and bake for 2 hours.