Heat the oil in a large pan that has a tight-fitting lid. Fry the onions with a pinch of salt over a medium heat for 10-15 mins until golden and crisp. Remove from the pan with a slotted spoon and drain on kitchen paper, leaving the oil in the pan.
Add half the ginger, half the chilli, all the garlic, spices, and both types of carrots to the pan, and fry for 6-8 mins until the carrot slices are starting to turn golden. Add the rice, stir briefly, then add the stock, a handful of the coriander, a good pinch of salt and grinding of black pepper. Bring to a simmer, and as soon as it starts to boil, turn the heat down to low, cover with a lid and leave to cook for 12-15 mins.
Meanwhile, put the remaining ginger and green chilli, most of the cashews and most of the remaining coriander in a small blender with 50ml water. Blend until smooth, adding another 2-3 tbsp water, if needed, to make a spoonable sauce.
When all the liquid has been absorbed into the pilaf and the rice is tender, fluff up the grains with a fork. Spoon over the coriander chutney, and sprinkle with the fried onions, reserved coriander and remaining cashews to serve.