Place saffron threads, cloves, peppercorns, cinnamon, garlic, parsley and 1 tbsp sea salt in a mortar. Pound with a pestle into a rough paste. Transfer to a bowl then add 100ml warm water.
Heat oil in a large saucepan or cast-iron casserole dish over medium heat. Fry the lamb in batches for 5-7 minutes or until browned on all sides. Transfer to a large bowl.
Fry capsicum, onion and carrot in the saucepan for 10-12 minutes or until softened. Add tomato and cook for 5 minutes.
Return the lamb to the saucepan. Add spice-and-water mix and wine, and stir well. Bring mixture to boil, cover and simmer for 1 hour over low heat, adding a little more water if necessary. Add the potato and cook for 30 minutes or until the lamb is tender, the potato is cooked and sauce is thickened. Serve with steamed rice.