Method

1. Preheat the oven to 150C/gas 2.

2. Combine the flour with salt and freshly ground black pepper. Spread on a plate. Turn the shanks in the seasoned flour, shaking off any excess.

3. Heat the oil in a flameproof casserole over medium heat. When hot, add the lamb shanks and fry until browned all over. Remove with tongs or a perforated spoon and set aside.

4. Lower the heat slightly, then add the onions, garlic and herbs to the casserole. Gently fry until golden and softened. Raise the heat and add the wine and vinegar. Bubble furiously for 2-3 minutes until reduced.

5. Return the shanks to the casserole. If you like a lemony flavour, add a couple of strips of lemon rind. Cover tightly with greaseproof paper and a lid. Place in the oven and cook for 2 hours or more, until the meat is falling off the bone. Turn the shanks from time to time, and add more wine if the liquid is evaporating.

6. Half an hour before you want to eat, start cooking the champ. Put the potatoes in a large pan of salted water. Bring to the boil then simmer for 15-20 minutes until tender. Drain in a colander and return to the pan. Cover and let them sit for a few minutes.

7. Put the milk and 50g of the butter in a small saucepan. Bring to the boil, then add the spring onions. Turn off the heat and leave to infuse.

8. Mash the potatoes, then beat in the infused milk until smooth. Season to taste and transfer to a warmed serving bowl. Make a well in the centre and add the remaining lump of butter to melt into the champ if you like. Serve with the lamb shanks.