Preheat your oven to 165c.
Place a large, heavy pan (an enamelled cast iron with a lid is ideal) onto the hob over a medium heat.
Season the lamb all over with a generous pinch of salt.
Add a splash of olive oil and the lamb shanks. Brown off nicely all over, this will take 5-10 mins.
Set the lamb aside, reduce the heat slightly and add the diced onion to the pan with the butter and a pinch of salt.
Cook until golden and soft, about 7 mins.
Add all of the spices, the tomato puree, ginger and lemon peel. Cook for another 2 or 3 mins until the spices are fragrant and everything is well combined.
Pour in the stock (taste it first for seasoning), rosewater and garlic and rub the saffron between your fingers to crumble it in.
Return the lamb to the pan and nestle in the quince around it.
Bring the stock to a gentle simmer.
Place a sheet of greaseproof paper over the top, then the lid of your pan and place the whole thing into the oven for 2 hours to 2.5 hours.
Plate everything up in a large serving bowl, squeeze over the lemon and sprinkle over the mint and pomegranate.
Serve over rice or with bread (or both!).
