Preheat the oven 260°c.
Heat the oil in a large casserole pan on a high heat, add the lamb shanks searing the shanks all over until golden brown. Remove from the pan and set aside.
Add the onions, carrots to the pan until the onions begin to soften. Add the garlic and cook for a couple of mins, stirring together.
Add the wine to deglaze the pan, then add the tomato puree, rosemary, bay leaves and season.
Return the lamb to casserole dish, pour over the stock and stir together.
Place in the oven and cook for around 2 hours, turning occasionally.
After 1hr 45mins, add the cornflour, stir and return to the oven for the remaining 15mins.
Serve with some mashed potatoes and green veg.