Combine half the onions, half the ginger, 'half the garlic, the saffron and 2 to 3 tablespoons of yogurt in a large bowl. Add the meat and baste well. Set aside to marinate for 1 hour. Melt the butter in a large saucepan. Add the remaining onions, ginger and garlic and fry until they are deep golden brown. Using a slotted spoon, transfer the mixture to a plate.

Add the meat mixture to the pan and fry until they are evenly browned. Moisten the meat with a spoonful or two of yogurt while frying. As it dries, add more yogurt. Stir in the onion mixture, chilli powder, dill, salt and any remaining yogurt. Reduce the heat to low and simmer the meat, stirring occasionally, for 40 minutes. Add a spoonful or two of water if the mixture becomes too dry.

Mix the almonds and cream together, then stir the mixture into the lamb. Cover the pan and continue to simmer the korma for a further 15 to 20 minutes, or until the lamb is cooked through and tender.

Transfer to a warmed serving dish and serve at once.