Put the lamb and flour in a bowl, season and toss to coat. Heat the oil in a large frying pan or casserole over a medium heat, then fry in batches for 5-8 mins until browned all over. Tip the meat into the slow cooker. Add the onions and carrots and cook for 5-8 mins until starting to colour, then stir in the garlic and cook for 1 min more. Scatter in any leftover flour and stir for 1 min. Stir in the tomato purée and cook for a few minutes more.

Pour the stock over veg, stir and bring to the boil. Pour the mix over the lamb. Nestle in the bay and rosemary, season and cook on high for 3-4 hrs, medium for 5-6 hrs, or low for 7 hrs, stirring occasionally until the lamb is tender. Once cool, it can be frozen for three months. Defrost in the fridge fully and reheat in a pan until piping hot.