Recipe courtesy of Rocket & Squash
- Preheat the oven to 170˚C / 150˚C fan / Gas 3.
- Drain the soaked chickpeas and transfer them to a large roasting tin. Pop the leek batons, garlic halves and oregano sprigs among the chickpeas, add the wine and water and place the lamb shoulder on top. Season generously with ground black pepper (but not salt, as this will toughen the chickpeas).
- Line up two large pieces of foil, pleated in the middle, so they can expand a little without ripping. Then seal the roasting tin tightly and cook for 5 hours.
- Meanwhile, make the chimichurri by finely chopping the herbs and combining with the other chimichurri ingredients. The earlier you do this the better, as the flavours mingle and mellow over time (in fact, if you could plan to do this the night before, as a prompt to remember to soak your chickpeas).
- After 5 hours, check the lamb; it should be soft and succulent, and if you gently tug the bones, they should feel like they’re about to slip out. If not, reseal, and give it 30 minutes more. If it’s good, then increase the oven temperature to 200˚C / 180˚C fan / Gas 6, remove the foil and, if the chickpeas look dry, pour in 200ml or so of water. Give the tin a shake and roast for 15-20 minutes to brown the top of the lamb.
- When the time is up, carefully remove the lamb from the tin and set on a plate. Squeeze the garlic halves so the soft cloves plop out and stir them into the chickpeas along with some salt and a little more water, if needed, to loosen things up.
- Decant the chickpeas, the leeks and all the juices onto a platter. Place the lamb on top, pull out the bones and push the meat into big chunks using two spoons. Season generously with salt, and serve with plenty of chimichurri over the top.