Wash the lentils and rice several times in cold water. Drain thoroughly.
Heat the oil in a heavy-based saucepan and add the onion. Stir-fry for 6—8 minutes over a medium heat and then add the spices.
Continue to stir-fry for 2—3 minutes, then add the rice and lentils. Stir-fry for another 2—3 minutes, then add the stock, tomatoes and fresh coriander. Season well and bring to the boil. Reduce the heat, cover tightly and simmer for 10 minutes.
Remove the pan from the heat and allow to stand undisturbed for another 10 minutes. Transfer to a serving dish and garnish with crispy fried onions. Serve immediately with pickles and natural yogurt, if liked.