- Preheat oven to 150°C/Gas Mark 2.
- Heat sunflower oil in an ovenproof casserole dish and sear the lamb shanks on all sides.
- Remove from the pan and set aside.
- Deglaze the pan with the lamb stock, scraping up all the browned bits that might be stuck to the bottom.
- Add the tomato puree, rosemary and season well. Remove from the heat.
- Add the quartered onions, sliced carrots and the peeled, separated cloves of garlic to the pan.
- Return the seared lamb shanks to the pan, cover tightly with a lid (or use aluminium foil).
- Bake in the centre of the oven for two hours, removing the foil/lid for the last 20 minutes of cooking so that the meat browns nicely.
- Carefully remove the lamb shanks and keep warm while you make the gravy.
- Dissolve the cornflour in a little cold water.
- Return the casserole pan to a medium-high heat on the hob and when the juices in the pan are bubbling carefully pour in the dissolved cornflour.
- Stir constantly until the gravy thickens. You might need to add some more hot lamb stock or more dissolved cornflour to get it to your desired consistency.
- Serve the lamb shanks and gravy with creamy mashed potatoes.
For best results, choose one of our range cookers with a slow cook setting such as the Chefmaster or Cuisinemaster. Cooking at lower temperatures over a longer stretch of time helps to fully release the flavours of this feast.