Heat two tablespoons of olive oil in a large lidded pan. Add the chopped onion and diced lamb and cook until the meat is coloured on all sides.
Pour enough water over the meat to cover.
Add a further two tablespoons of olive oil, the salt, freshly ground black pepper, ground coriander, ground cinnamon, cinnamon stick, ground cumin, ginger, saffron and saffron water to the meat in the pan and bring to the boil.
Turn the heat down, put the lid on, and allow the meat to simmer for about two hours.
Add the soaked prunes and leave to simmer for a further 20 minutes.
Stir in the honey and sprinkle the tagine with orange flower water and serve hot.