Cook the rice following pack instructions. Meanwhile, heat a large non-stick pan or wok and dry-fry the cumin seeds for 1 min, stirring often, while they pop. Remove and set aside.
Using the same pan, heat the oil, add the onion, garlic, ginger and chilli, and sauté over a medium heat for about 3 mins. Reduce the heat, add all the spices, stir well and cook for a further 2 mins. Add the tomatoes, stirring, and use the side of a spoon to break them up into smaller bite-sized chunks. Add the chickpeas and 200ml water.
Bring to the boil, then simmer for 10 mins before stirring in the lemon juice and spinach. Let the spinach wilt, then remove the pan from the heat.
Divide the rice between 2 bowls, and serve the curry. (The flavours intensify as it cools, so for a fuller flavour, make earlier in the day and reheat slowly prior to serving.)