Place the lamb in a large mixing bowl and rub all over with half of the sunflower oil. Sprinkle the spices on top and some seasoning all over, mixing well with your hands. Cover with clingfilm and chill for at least an hour.
Heat the remaining olive oil in a large casserole dish over a moderate heat until hot. Fry the garlic and ginger, stirring all the time, for 1 minute, then add the lamb to the dish. Stir well, then add the onions, cooking and stirring for 1-2 minutes. Add the water and coconut milk, bring the mixture to the boil, then reduce to a simmer.
Cover with a lid and cook for 70-80 minutes until the lamb is soft and falls apart easily. Remove from the heat and adjust the seasoning to taste. Spoon into serving bowls and garnish with the green chilli, poppy seeds and a few saffron strands.
Freezing and defrosting guidelines
Cook as instructed and allow to cool completely. Then transfer to an airtight, freezer-safe container, seal and freeze for up to 1-3 months. To serve, defrost thoroughly in the fridge overnight before reheating. To reheat and serve, place on medium heat, stirring occasionally until the dish is heated through.
For top tips on protecting you and your family when preparing raw meat and poultry, visit Food Safety in the Home and view the full Food safety at home video.