Method
Place the butter and oil in a large saucepan over a low heat. When the butter has melted, add the onions and continue to cook over a low flame for about 10 minutes, until the onion has softened and begun to colour. Add the garlic, stir well, then tip the chickpeas and tomatoes into the pan. Next, add the pepper, turmeric, ginger, cinnamon and lemon juice and stir to combine. Slowly pour in the stock and add a pinch of salt, then bring the pan up to the boil. Let it simmer for about 25 minutes - the liquid should reduce considerably, but don’t let it get too dry (you can top it up with more stock or water if needed). When about five minutes of simmering time remains, add the chopped coriander (reserving a little for serving), chopped mint, paprika and cayenne pepper to the pan. Stir it all in, then add the lamb and check the seasoning, adding more salt and pepper if necessary. When the five minutes are up and the lamb is properly heated through, sprinkle over the remaining coriander and serve.