Put the rice, curry powder, turmeric, cinnamon, cardamom (if using), salt and water in the rice cooker, give everything a good stir and cook. About halfway through cooking, stir again so that the curry mixes in well with the rice.
Whilst the rice is cooking boil the eggs till they are hard boiled, then peel and quarter them and set aside.
When rice cooker has switched off the cook setting, let it sit for about 5 minutes in the keep warm setting.
When the rice is ready, slice the spring onions and shred the smoked mackerel.
Heat oil in a pot and stir fry the spring onion for a minute.
Then add in the smoked mackerel and fry for a couple of minutes.
Fluff the rice and add it in to the pan with the yoghurt and lemon juice, mix well and adjust seasoning.
Serve topped with quartered eggs (and lemon wedges if desired).