1. Heat the oil in a large saucepan over medium-high heat. Add the mustard seeds and cook for 1 minute, shaking the pan often, until they begin to pop.

2. Reduce the heat to medium. Add the onion and butter and cook, stirring often, for 5 minutes, or until the onion is golden. Add the rice, cardamom, coriander, and rice and stir for 1 minute, until rice is coated.

3. Stir in the stock and salt, increase the heat to high, and bring to a boil. Reduce the heat to medium-low and cover. Simmer for about 17 minutes, or until the rice has absorbed all the liquid and is tender.

4. Transfer to a warmed serving bowl. Sprinkle with the cilantro.

Variation: Persian-style Rice

Cook as above, replacing the onion and spices with ½ tsp salt. Tip the rice out of the pan and keep warm. Wipe out the pan, and, while still hot, brush with 2 tsp oil and dot with 1 tbsp butter. Line with a layer of thinly sliced raw potato. Return the rice to the pan and dot the surface with another 1 tbsp butter. Place a clean kitchen towel on top of the pan, replace the lid, and cook on the lowest heat for 45 minutes, or until the potato is cooked and slightly crisp. Turn off the heat but do not remove the lid. Let stand for up to 2 hours before serving.