Put the rice in a pan with the cardamom pods, a pinch of salt and the coconut milk and add enough water to come one finger’s-width above the rice. Bring to a simmer, put a lid on and simmer for 10 minutes or until the rice is cooked through. Meanwhile, put the lentils in a pan with the onion, ginger and turmeric, add enough cold water to cover by 2 cm and simmer until tender and mushy and the water is absorbed, about 15 minutes adding more water if you need to. Heat a little oil in a small pan and add the cinnamon, chilli, mustard seeds and curry leaves and keep heating until the seeds start to pop. Tip into the lentils, season well with salt and stir. Serve over the rice.