Preheat to oven to 150 degrees C. Heat oil in a large, heavy based frying pan, sear the shanks until golden brown, and then drain on absorbent paper. Transfer to a deep roasting dish.
Add onions, rosemary and garlic to the frying pan and cook for 1 minute or until golden. Then add the red wine and beef stock to the shanks.
Cover with baking paper and foil, and then cook in the oven for 1 hour before turning the shanks over and cooking for a further hour.
Spoon on some red wine sauce and serve with mashed potato and steamed green vegetables.